It really doesn't matter. Both the colleges are at par and both the colleges have very ordinary teaching faculties.
I personally would have chosen NLUJ, the sole reason is because it has a smaller batch compared to GNLU but if I wanted a more stress free environment then I would have gone for GNLU. Also, if finance is an issue then GNLU is cheaper. In terms of placements both the colleges are at par but NLUJ is still slightly doing better especially when we talk about recruitment in foreign firms. If you want to go for litigation though, GNLU provides a stipend of some sort so you can consider that too.

I have tried to be objective with my answer but I personally feel you can't really go wrong because both the colleges will give you ample of opportunities.

"Please guide me on which of the above 2 colleges should I put above in the preference list." My brother in christ what preference list? the list is filled post result declaration. Not to demotivate or disparage you but pls don't count your chickens before they've hatch.
Assuming you are not a troll trying to flog the GNLU v NLUJ dead horse, here's arguably the most sensible course of action:
Firstly, score well.
Then, once you have the pre-requisite score, start worrying. Connect with seniors from the both the Unis on LinkedIn and explain to them your predicament. Try connecting with kids senior to your immediate senior batch. You'll get more comprehensive and complete replies. Do not worry, people do reply.

As a fellow NLUite who has been to many NLUs, here is my opinion -

Placement statistics of GNLU are good for now. But the major thing that hurt me about NLUJ was their campus.

The campus is literally in shambles. Just see the hostels or students there, you'll know.

NLUJ's quality of students is good, as no domicile, and OBC reservation is there. GNLU gets hit badly in this regard as they've implemented EWS, OBC, Domicile reservation.

It might seem like I'm playing the devil's advocate here but I'd suggest GNLU for the main reason that it seems like it has the potential to get better in the future. Kind of like how NLUD has gotten better than its rival NLUs in the last 10 years or so. NLUJ has stagnated to an extent although I don't think it's declined by much in comparison. But, I think GNLU has the potential to challenge NUJS for 4th place if it continues to receive state support and funding. NLUJ has suffered due to administrative laxity despite a bright student crowd. I think GNLU might be a better choice over the long-term.

Not OP but I’ve seen that any mention of NLUD seems to attract these trolls who question its superiority since their ego is too fragile to accept that a much younger law school has overtaken their alma mater. A student who gets into both NLUD and NUJS or NALSAR these days would usually prefer NLUD. Especially over NUJS. These are plain facts based on CLAT preferences.

And anyone with half a brain knows that the VC leaving had more to do with regional politics than some personal gripes. The guy is still an NLUD employee on deputation to Nalsar, fyi. As far as faculty leaving goes, some have gone for higher studies and others went only to NLS, not any of the other NLUs. Regardless, they contributed enough to the institution and may want a new experience. The faculty quality is still better than at NUJS and NALSAR despite the mini-exodus. But I’m sure you’ll continue to be in denial.

That is because "any mention of NLUD" always seems to come in the form of declaration of their supposed superiority over other NLUs, which has never actually been proven in any form in the real world. Maybe if you just discuss NLUD's achievements and give the credit to their students, faculty and admin, like normal people do, then you won't face such reaction.

No domicile quota (yet) unlike the CLAT top 3, better infrastructure, continuous funding for the research centres, better urban location and Delhi is more 'national' in character than other NLUs, still better faculty than all the remaining except NLS, placements are better/at par percentage-wise than older ones like NLUJ and GNLU despite smaller batch size, more moot, debate and ADR wins than many older NLUs, scholarships aren't scarce either, graduates from the first batch are becoming partners at law firms. The list goes on. At this point, you should ask which other NLU NLUD isn't better than. The answer will be - hardly any.

Half of your claims are unverified assumptions. Better urban location? Certainly not compared to the likes of NUJS. Better faculty than any other NLU apart from NLSIU? What's the metric to prove that exactly, especially with people like Aparna, Mrinal, Arul and Chinmayi all having left? You can keep trying to make such claims. Won't make that true. Insofar as placements go, NLUD has always been behind NLS, NALSAR, NUJS etc. Grads from first batch becoming partners, lol. Which good nlu hasn't had that already? Funding for research centres is still there but other than Anoop's work, who is doing anything useful with that funding that is better than what's being done at other NLUs? More moot, ADR wins, really? No stats to support that, clearly. Stop trying to prove your pseudo superiority. You are just coming off as desperate. Get some lesson from nls. You don't become the best when you keep saying that, you become better by everyone else acknowledges you to be the best.

That's the thing, though, I'm not trying to convince you that NLUD is better. I know it is and I have stated reasons for that and your acknowledgement of that or personal opinions won't change anything. There's enough verifiable facts for all the claims made, just because you're personally unaware doesn't make them false.

Comparing urbanism in Kolkata and Delhi as far as the legal profession goes is naive. There are enough stats to support the moot, debate and ADR wins. Check the archives of this website itself or the websites of various NLUs, if you're so keen on stats. Stats also exist to support the placement claims improving year-on-year. Apart from NLS, the other NLUs hardly have any research centres comparable to 39A, CCG, CIIPC, etc. Again, ignorant to say that their work is only as good as those from other NLUs when you are clearly unaware of the engagement and work being done. Faculty leaving happens, and while one of them went for higher studies, the rest went to NLS only, not to any of the other NLUs. Mrinal and Aparna are a couple and are also NLS grads anyhow and the NLS VC is on a recruitment spree. To reiterate, check the faculty profiles and you'll see that NLUD's is still better than the others barring NLS.

Overall, your comment strikes me as a lazy and biased attempt to dismiss the competitive achievements of NLUD by claiming that facts are "assumptions" when they actually aren't. Getting a tier-1 partner in less than a decade after the first batch graduated isn't that simple although I can see you're trying to play it off as normal for any "good NLU". Try harder to actually engage next time by bring facts to the table. Until then, stop wasting mine and your time by commenting.

Okay, since you want engagement, here it goes.

1. There is stats to support that NLUD students win competitions. There is also stats to support that students from NLSIU, NALSAR, NUJS, also win them in equal or more numbers. There is NO stats to show that NLUD wins more of those, as you claim. You are the one who is making the claim, so you are the one who should be adducing the proof.

2. As for research centres, faculty run those centres and their performance depends on those very faculty. With Arul having left, CIIPC is hardly with any such leader. CCG post-Chinmayi has not really delivered anything great. Even if you consider the performance of those centres, other than 39A, the cumulative research output is not anything extraordinary nor has made any considerable contribution to the Indian legal research ecosystem. You are the one who in turn is unaware of the work being done in the other NLUs, so claiming that you are doing 'better' work without such knowledge shows your laziness and not mine.

3. As for faculty profile, I did check that. Did not find anyone extraordinary compared to the other NLUs other than Anoop. Even Daniel is a good teacher that I am aware of, but there are plenty of similar others in other NLUs too. Other than vague claims about the greatness of your faculty, what else have you shown to back up your argument exactly?

4. You 'know' that NLUD is better than other NLUs and are not out trying to convince anybody else of that fact, as per your own comment. So why on earth are you even keeping up the comments? Stay safe, sound, quiet and secure with your knowledge. What you have been doing instead is exactly what you are claiming not to be doing, which is to convince others that NLUD is the greatest without actually having any any proof of that.

5. As for the university in general, while I respect its students and faculty, it is one of the most unethical NLUs in the country. Year after year it keeps fleecing law aspirants in the name of a separate 'quality' exam and also keeps supplying false data to NIRF and other public authorities. Those should enough reasons for its fanboys to keep a low profile, but instead they keep crawling out of the woodwork everywhere to claim its greatness at every possible opportunity.