As you said your father is a single handed property owner and missing since 2008. First of all,who is in possession? Whoever in possession,even your brother,you go to your father's home and stay there and tally all your documents staying from childhood in the same house n all birth certificate, ration card,pan card,adhar card ,bank passbook etc must show your address as the same as your father.
Check up complaints details records from 2008 of missing complaints of your father made. Collect latest status of your missing complaint from police station.