Can the brother sell the property?

hello, we have a property of 7000sq ft house which was built by granfather and it was divided equally between my father and my fathers brother after my grandfathers death my grandfather did not did any will or writings their son's itself divided the property my father got expired 12years back after my father death my father sold his share of property and went off wen i was in minor and we not aware of this what my fathers brother did was after he sells his property the remaining half property is between my grandmother and my mother and in the agreement hr mentioned like after my grandmothers