Hello, Sanket

Look JEE mains and advance is conducted every year and each of them has separate reservation and cut-off for different categories. There is some NIT where you can apply.

If you consider the year 2016, The opening rank of some NIT's  was 24 and closing rank was 5431. For computer science and engineering, the following was the opening and closing rank based on different categories.

Category        opening rank        closing rank

Gen                     65                      5550

OBC                    634                    2328

SC                      329                      1756

ST                      1358                      1568

Now Based this you can get an idea how the seats are going to be filled this year. For more information, you can visit the following website 

https://www.collegepravesh.com/engineering-colleges/nit-delhi/

I hope you find this information useful. Have a great future ahead.