My great grandfather had two sons. He made a will for his property wherein he made partician/divided his property into two equal parts for both sons. Elder son has no children, whereas younger son has 4 childrens. After my elder grandfather died. My younger grandfather transfer his property rights to his name. my younger grandfather also died and he has written in his will, that after his death her wife (my grandmother) owns the property, after my grandmother death it will be distributed among 4 childrens (3 sons & 1 daughter ). Now after father death, nobody is taking care and providing food to my grandmother expect by her daughter (my mother). So my grandmother had talk to his two sons (elder sons) and decided to divide the property in 5 parts. one share each for 3 son, 1 for daughter (my mother), 1 for grandmother herself. Now grandmother and two elder son has decided to gift their share in the property to my mother expect 1 son. All legal documents for Gift Deed has been made & registered and their share in property has been gifted. Now my mother has 4/5 share in the property. In the document it's mentioned that 1/5 of the share is kept aside for the last son. Is there any chance that last son can dispute this gift deed. If he approach court to cancel this gift deed given to daughter by mother & by 2 elder brothers. What legal course should we follow to cancel his dispute or his request.