Property

Dear Sir ,

I required ur urgent help

My uncle has 03 acres of land. He in drunken condition made an sell agreement to sell it on a Rs 100/- stamp in witness of some people and taken Rs. 100000/- advance from third party, which is not made notery nor it is registered sell agreement. Now he do not want to sell the same. But the party want to purchase the same forcefully. What he has to do to save the land? what is the validity of this agreement in court?