Hello Shubham,

The basic eligibility criteria for NIT usually take into account the percentage obtained in boards. You need to secure minimum of 75% marks in 12th if you are a General or OBC candidate or be in top 20 percentile of a boards result. In case you are SC on ST candidate you need to secure a minimum of 65% to be eligible for NIT.

No matter how you percentile is if you are not able to clear the eligibility based on the 12th percentage you cannot get a seat in in any NIT.

I hope this helps. 

All the best.