Hello Mukesh,
In 80 %ile your SC Rank would be around 9,000 and To be honest ! There is only 1 percent chance of getting the lowest NIT with the lowest branch.

Just download the NIT Josaa app on playstore and see the colleges at this rank last year !

Instead you should try for some private colleges ! Coz even if you get nits the possible branches would be earth sciences or production engg which ain't satisfactory !