Property distribution

Not yet. Assuming that ur a member of the mitakshara school of law and that your grandfather has expired without making a will, the property is now jointly owned by your grandmother as well as all of their children. 

In case your grandmother wants to sell the property, first she needs to get the relinquishment deed signed by all the other heirs thereby relinquishing their share to her.SUbsequent to that she can sell the property

If it is the self acquired property of your grandfather who died intestate, the entire property will devolve upon his all his legal heirs equally.  Your grandmother can sell only her legitimate share out of the undivided property of your grandfather.

You may obtain succession certificate and thereafter the grandmother can release her rights in the property in favor of her legal heirs.

Adv.Augustin and Adv.Kalaiselvan are correct, Mr.Wealth Manager Kindly advice properly if you don't know the rule please avoid to advice don't misguide, this is professional's forum.

You are right Mr Professional Jayakumar. Read my answer first before jumping to your own sweet conclusions. 

Obviously, there will be sons/daughters of the deceased grandfather, and their rights, too, will have to be taken into account. And since it is a piece of land, the collector will want to know the legal heirs of the deceased for which a succession certificate may be asked. Only after the rights, shares, interest of the legal heirs in the property are determined, can the grandmother release her share of rights in favor of her sons/daughters.