How do i prevent my rowdy son from getting my property?

You can disown your son by making publication to this effect in two national news papers, one is English and the other is Hindi or any regional language news paper. You may also file a suit seeking decree that you have broken all ties, including the blood relations and have also debarred him from inheriting all movable and immovable properties. However, if the property is self acquired property then you can execute a Will in favor of anyone else and may not need to file a suit.

If it is a parental or ancestral property, then you cannot disown him from that property. In this regard, it is to be noted that a pre-requisite condition required for a property to be Ancestral property is that it should be owned by the great grand father followed by grand father, father & present generation all in this linear generation living & enjoying the property.

The property should not have ever partitioned & shared or distributed to any of the Hindu Coparceners as in any linear generation as mentioned above, in other words, it should be an intact single property which is being used jointly by all members of the Hindu Joint family. Therefore, all property inherited by a male Hindu from his father, father's father, or father's father's father, is an ancestral property.

The essential feature of inheritance of an ancestral property according to the Mitakshara law under Hindu Succession Act is that man inherits from any of his three immediate paternal ancestors, namely, his father, father's father and father's father's father is an ancestral property as regards his male issue, and his son acquires jointly with him an interest in it by birth. Their rights attach to it at the moment of their birth. 

Therefore, if your property falls within such ambit then your son is entitled for the share in his Grandfather’s property. Furthermore, in view of above mentioned, the basic proposition is that the grandson acquires a right in the property of his grandfather at his birth and has a right of inheritance jointly with his father at the time of succession.