Civil suit - need ur suggestions

Hello Sir, I have one problem i have got one house in the name of my mother in Hyderabad and recently my mother has expired without writing a will my father has expired very long back and we are (3) siblings (2) brothers and (1) sister and to my dismay my sister has also expired in the month of April, 2011 and my brother who is pshyic disorder patient has left the house and missing since June, 2012 and main probelm is that i haven't got the Death Certificate of my sister and i have got Death Certificate of my mother and i have even got the FIR copy of my brother missing case and recently i have applied for NOn-Availability Certificate from GHMC and after getting it i have to approach the Revenue Divisional Officer concerned for issue of Death Certificate of my Sister and we have planned to dispose of the property one more thing i have got burial ground report of Sister Death as a proof.  Can i file a suit in a Civil Court for issue of Legal Heirship Certificate and if so how much time will take to get the Legal Heir Certificate

Please Help me out