Rights of son on the properties which were acquired by him.

Hello Lawyers, My Grandfather (Hindu) has 1 daughter (E) from his first wife and then 4 sons (A,B,C & D) from his second wife. A & B purchased three properties on my Grandfather's name, the entire payment was done by A & B but the properties were registered on my Grandfather's name. Three questions:- A. Can A & B legally stop C, D & E from claiming any right in the properties, as the money for purchasing the properties was entirely paid by A & B. Can they? B. If my Grandfather demises without any will, then what would happen. Whether only A & B will be allowed to share the prprt