Dear Saurabh,

To get admission in best NIT's and IIIT's you need to score very high percentile which is definitely 98 percentile or above, and for top branches you need to score more than 98 percentile. There is also a chance if your percentile is 95 or more, then by participating in CSAB round you can get some decent NIT's and IIIT's. To check your rank according to your percentile you can go with this link to know https://engineering.careers360.com/articles/jee-main-marks-vs-percentile

Your marks should be around 130+ to get a seat in NIT or IIIT.

Best wishes.