Dear Applicant,

I hope you are doing well.

The basic requirement for BCA is 12th class certificate and you must pass in all subjects.

If you want to go for BCA you will have to start from first year itself since commerce has no link to bca they are 2 completely different fields . Using your markshhet on 12th science you can get bca admission.

Some colleges take students based on entrance exam that they conduct.

Others need maths or science stream compulsory.

Basically any stream students can take bca.

Clear your paper of 12th.

Hope this helps