Uncle bluffing to sell property what can we do

my grandfather left us his land .its divided among his 3 sons and his wife.my grandmother gave her share to my dad since she is living with us for past 21 years and my parents are deaf. we want to sell the house as its really old and was affected by recent floods in chenai. my uncle promises to sell the land and when the time comes he gives excuses. he takes advantage that my parents are deaf. he stopped talking to my grandmother because she gave her share to my father. for the past 4 years he is making a fool out of us.what should i do????????