Hi Sreeja!
As you have written MAT exam, I am assuming you want admission in MBA. So, now you need to fill the application form available online on the official website of NRTI. LINK:

https://www.nrti.edu.in/admission-updates/

The application fee for general/open category students is 500 INR annd for reserved category candidates it is 250 INR. Once you have submiited the application successfully, you will be called for interview round. If you qualify this, then you will be given seat according to the counselling procedure.

Thankyou!