Since your father died intestate apply for and obtain letters of administration from district court in respect of property standing in name of deceased father
2) enclose death certificate of deceased father and consent affidavit of other legal heirs
3) it takes around 6 months
4) apply for mutation of property in name of legal heirs
5) your mother and sister can execute gift deed or relinquishment deed for their share in property
6) if you want legal heir certificate you have to file petition on district court in this regard .it is not for transfer of property but only identifies legal heirs of deceased