Hello student.

A rank of 12621 is a bit of low rank for you to fetch you a seat in amritha campus in open quota. And the branch of computer science is a demanding one. NOt just that branch, branches like computer  science, electronics and communication engineering, electrical and electronics engineering etc are sort of demanding branches.

There might be chances to get computer science. Might be in 2nd round or 3rd round of counselling. Apply for the university, attend the counselling. People might not be attending because, they might be preferring nit's and iits and other higher ranked colleges etc. But we cant be sure about this.