Varsha, the official website https://bcdd.kerala.gov.in/schemes/educational-schemes/oec-postmatric-educational-assistance/ states that the Candidate should be listed in OEC list and should have secured a seat in merit and reservation. Now if you belong to Kerala and want to study in Self financing Medical Colleges, you can apply only through State Counselling for Management Quota and not Government Quota seats. Now OEC is a State level Reservation for Candidates belonging to Kerala and it is not applicable in Tamilnadu. And so you might not be eligible for Post Matric Scholarship.