Hello Prince,

For admission to National Institute of Technology (NITs) you need to appear for JEE-Main examination in which you have to secure good marks and also you have to secure 75% or more marks in 10+2 or it's equivalent from any recognized central/state board. So without scoring 75% or more in 12th you are not eligible for admission to any of the NITs.

IFor more details about JEE-Main 2020, you should read this article .

I hope this answer helps you.

Good Luck!!