transfer of plot from deceased son to mother

Hi,nmy bachelor friend,has died recently and had a plot in bangalore in his name.now the property needs to be transferred to either his mother or sister(Surviving ),but both are out of karnataka .He has not prepared any will .nQ1.How to transfer the property to the mothers name ?nQ2.Bangalore advocates are asking for local address addhaar,is it necessary or if the address is nonkarnataka,will it do ?