Hello

Since you belong to the Scheduled Castes but converted to Christianity, the SC reservation usually does not apply after conversion.
Most government exams like JEE give SC benefits only to Hindus, Sikhs, and Buddhists, not to converted Christians.
You should check if your Christian sub-caste is listed under the OBC (Other Backward Classes) category. If yes, then you can apply under the OBC reservation.
If not listed under OBC, then you may have to apply as the General category.
You can also try for EWS (Economically Weaker Section) if your family income is below the limit. It’s best to get a caste certificate from your local authority based on your current category.