If you are from CBSE board and you belong from ST/ST quota then only otherwise you are not eligible to take admission in any NIT or any college which take admission through JOSAA. Otherwise, check whether your percentile falls in the top 20 percentile of your respective board. If yes, then you are applicable to take in above-mentioned colleges.  

Hello

You have not mention your category.The minimum eligibility is 75% aggregate marks in 10+2 for general category and 65% for SC/ST/PWD students.

Hope for the best,best of luck.

Nope samant. It is a clear cut information released by the government colleges like IIT and NIT every year that they won't allow the admission of the students having their boards marks less that 75%. So there is no chance to get any NIT.