Can my mother wrtie will according her wish.?

We are Living in Guntur,Andhra pradesh. My mother got property from his grand father....my mother has 4 kids....2 daughters and 2 sons...my mother wants to share her propery like this...

 30% property to 1 son

 30% property to 1 daughter

 20% peroperty to 1 sonn

 20% peroperty to 1 daughter

 Can my mother write will accoding her wish? is it leagal....pls give reply