How to enforce vested interest in biological father's property

After my biological father died , my mother got married after some years again . There is no deed of adoption in the eye of law has been done . But in my school certificates , college and in other documents my father's name is my second father's name , instead of biological father . Do I still have share in my biological father's ancestral property ? Does my mom have right to give power of attorney to anybody when we (me n my brother ) were not adults . If she does this because of some pressure or in lack of knowledge of legal advise , can I claim to get my ancestral property ?