Getting CSE in sastra university is a very tough in this competition. You must get less than 300-400 rank to get seat in CSE. Since you are from tamil nadu you can get seat in IT this is similar to CSE . If you were unable to get CSE in sastra my wish for you is to join in IT . I wish a very good luck to your bright future.

I will provide a link for sastra auniversity . You can get more information there

https://sastra.edu/