Branch you get will depend on factors like the rank you get in JEE mains examination and the category you belong to.

You can use the college predictor to predict the college and branch you can get-

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ic i=qna_answer

You can also go through this link to check the cutoff of top NITs -

https://engineering.careers360.com/articles/jee-main-cutoff-for-top-nits

Hope this helps you.