Hello Rahul, 

Congratulations on your 91 percentile first of all.

Secondly for applying for admission in NIT silchar, you need to appear under the eligibility criteria that includes:

1- Applying for the JEE (mains) examination

2- securing Atleast 75% in your class 12th board examination which is modified to 65% for SC/ST/OBC 

Considering your amazing percentile of 91% you should be eligible for admission in the states college. 

Now there might be some other criterias that are specified by the college apart from these for which you would like to get in touch with the concerned college authorities. 

I hope this helped.