Legar heir

The property of your  grand mother will devolve upon your father and his sister , the devolution is automatic by poeration of law, you need not obtain heirship certificare as is asked for , you have to simply make an application for mutation  of your fathers name in place of the grandmothers name, pedigree showing  your grandmotheres decendents  these decendents would be only two, your father  and his stoster , which  has to be verified ,.the officer keepng the record will send notice including a pulic notice to all concerned if they have any objection to the mutation  as prayed for, the sister of your father may also object but as you have stated that she has released her interest in favor of your father ,she also will appear and file her consent stating  no objection  by affidavit or  by production of a registered relaese deed  and thats all for you , the revenue authority will get it mutatied  as prayed for