Hi.

Since you did not mention any specific NIT, I will provide stats taking consideration of NIT Trichy (one of the top NITs)

So to get and admission in NIT for ST Candidate with Home State Quota you need to get less than 13000 rank which means approx. marks 145+

If you are under Other State Quota then, you need to get less than 1817 rank.

Please note, that these are category ranks and there is no exact category to marks information available due to the volatile nature of the exam.

If you have a further specific query please feel free to comment.

Best of Luck.

Anything above 95+ percentile could fetch you top NITs whereas 90-95, you have good chance to get into average NIT/IIITs i. e, around 130marks in jee mains  could land you in one of the top NITs.