Daughter rights in father property

Respected Sir, I need your valuable suggestions on my mother issues, were my mother grandfather has few agriculture land and home property and it's been settled to his four son equally using a kurra cettu- local agreement during 1966. In that one of the son is my mother father and for him family members are 3 sons and 2 daughter (including my mother). Recently came to know that my mother father executed a family settlement to the sons equally and my mother and his sister not aware of it and registered in register office on 2013. Do we(my mother and my mother sister) have any rights to fight as the property came from the grandfather considering as ancestor property?