They're both at the same level. Only big difference is the campus. NUJS is cramped and dirty but in the center of the city, NALSAR's campus is huge and full of greenery but it's on the outskirts of the city.
NALSAR too has domicile reservation. Moreover, the introduction of a new specialisation has got nothing to do with 'destroying student quality', as anyone with basic idea about education is aware of. For someone to claim that a STEM-related specialisation is bringing down student quality is preposterous, especially when the law subjects, faculty and other resources remain the same (if anything the BSc students have got better new hostel facility). However, despite being from NUJS, I would keep NALSAR slightly ahead as on date if I am advising a CLAT aspirant, but the reason for that is increased state interference at NUJS, as compared to NALSAR, where such interference has stabilised by now, though it remains to be seen what happens after the latest round of elections. Opportunities will be more or less the same to any enterprising student no matter what choice they make.
Top 5 ranking now: NLSIU>NLUD>NALSAR>NUJS>GNLU
Top 5 ranking 10-20 years from now: NLSIU>NLUD>NALSAR>GNLU>JGLS or MNLU-M