Hi Avinash,

If you get 81 percentile in JEE main exam, you rank would be approximately in between 2,00,000 to 2,01,000.  Also, Above is the range of your possible rank. The predicted rank may vary due to JEE Main tie breaker rules for the same score. For NITs, You have to secured minimum of 30,000 rank, which would be equal to approx 160 marks. You will also not get AIT pune with this rank.

If you have secured this rank you have a chance to get these colleges:

SAE Pune

IGEC Jabalpur

PTU Punjab

Amity University

MIT Academy Pune

UIET Punjab

These are few colleges, you will get on these marks.