Yes,why not 80 percent score in competitive exams is quite good.

In my opinion you can get nit, not the topmost but middle rank nits.

For more confirmacy google  nit cutoff rank for jee main you will be definitely satisfied with it.

If you are having any category then it is again a good news for you.

Hope my answer was helpful.

Sorry but the closing rank for NITs or other government colleges is around 25k and for core engineering branches you need less than 15k rank. So you can't get NIT with this rank however you may get admission in other private colleges affiliated with jee mains. To predict them please go through the jee main college predictor tool given below.

https://engineering.careers360.com/jee-main-college-predictor

Hope it helps.