Most SC judges are from MU / DU and this will remain so.
As a pure numbers game, there will be very very few NLU grads who survive / thrive in litigation for 20 years. Compare that to hundreds or thousands of law grads in each public university taking up litigation.
In the US most SC judges are from Harvard/Yale. We currently see the reverse in India, but there will perhaps come a time when the Indian SC is dominated by NLSIU alumni. It will perhaps be a combination of HC judges being promoted (Bobby Saraf, Aditya Sondhi etc) or appointments straight from the bar (GShanks, Menaka G etc). But how may years will it take for that to happen? And will the necessity of regional representation on the bench hurt the chances of those from large states and favour those from smaller states? Also, if the BJP dominates the scene in the next 25 years will this hurt the chances of NLSIU alumni, since most are left-wing and the BJP will prefer right-wing judges?
As a pure numbers game, there will be very very few NLU grads who survive / thrive in litigation for 20 years. Compare that to hundreds or thousands of law grads in each public university taking up litigation.