Legal validity of property settlement document of ancestral property

My Question is related to inheriting my Grandfather's property and ancestral property between my father and other legal heirs. My Father is the only son and he has 4 sisters, 2 younger and 2 elder. They came into a settlement few years back that my grandfather's property hereby solely belong to my father and other property in my grandmother's name(purchased by my grandfather) can be shared within the sisters and my father does not claim rights on the same. Based on the settlement document which was duly signed by all the legal heirs, my father accepted to vacate,sell the house which we were living and share the amount within the legal heirs amicably.Once my father shifted from the house, the sisters agitated and did not agree to act as per settlement. Can my father move any further legally based on the settlement document as to claim grand father's property ?