Hi,
There wasn't any formal dress code for law students earlier but when NLSIU Bangalore class wore shorts to class then it took notice of that and wrote a letter dated April 7, 2016 to the Registrars of the law universities and the principals of all Law colleges of India and wrote, "... the Committee recommends that the matter is left to each university/college to decide in respect of dress code what is feasible befitting the profession in this regard. It would be preferable, if the college follow dress code white shirt with trouser (white/black/grey) "

It means there could be a dress code depending on the option exercised by that particular institute.

I hope it helps!