depends on which college you obtain your degree from and what firm you end up working for. if you do not work for a firm and work instead for an advocate, anything over 20000 is optimistic (by current standards). if you work with the best corporate firms in the country, anything between 8 and 15 lakhs per annum. if you work with any other firm, could be much lesser.
the probability of your ending up at a tier-1 firm is higher if you obtain your degree from a top-4 NLU, simply because the firms have a reputation to depend on, although the newer NLUs are also performing quite well. I have also seen GLC, Symbi and ILS grads at these firms. If you manage to wangle a training contract with a foreign firm, the pay is exponentially higher.
In south india it is quite common for reputed firms to be stocked in the majority with associates from local colleges (such as UILS and BILS in bangalore), and the bias towards NLUs is not as pronounced as in Mumbai.
In my experience, engineering does not pay as much as may be earned by a law grad from a top-4 (NLS, Nalsar, NUJS, NLUJ) NLU. However it depends on the job you take up, as also the city. I have spoken to associates from large and small firms and they overall agree that a CS degree while providing a little value, does not provide enough to swing the vote in your favour if nothing else is good. Smaller 'diploma' courses which Ms. Surbhi Bhatia above refers to, also only make sense if your college does not teach these subjects as part of a regular course. I am unaware of what her college is or who she is in contact with, but all of my friends in corporate law, without exception earn more than engg grads. However I have never known anyone to earn 50 lakhs either (unless it is per annum and close to some salary provided by a foreign firm)
I hope this clears some things up.