It's unlikely to secure a seat in CSE at Amrita University, Bangalore campus with an 83.2 percentile in JEE Mains 2024, even with your OBC reservation.

Amrita University has historically had high cut-off percentiles for CSE, especially at the Bangalore campus. While they don't release the official cut-offs publicly, previous years' trends suggest scores well above 95 percentile for the general category and potentially even higher for OBC in the Bangalore campus.

There are a limited number of seats reserved under the OBC category. With many students likely scoring higher in the OBC category as well, the competition for these seats can be intense.

Amrita University offers various engineering branches besides CSE. You might have a better chance of admission in branches like Information Technology, Electronics and Communication Engineering, or Mechanical Engineering with your current percentile, especially considering the OBC reservation.

Amrita University conducts its own entrance exam (AEEE) for admission into various engineering programs. While JEE Mains scores play a role, a good score in AEEE can improve your overall chances of securing a seat, even in CSE (though it might still be a reach).

https://www.careers360.com/university/amrita-vishwa-vidyapeetham-coimbatore

I hope it helps!