Inam land- For ORC.

My Inam land is in GHMC(Hyderabad) LIMITS and in revenue pahani it is recoreded as 'Abadhi' in part of land . How to obtain ORC from revenue authority if it not possible who should i approach for get ownership certificate ( part of the land is OPEN LAND VACANT POSITION), i have already applied to RDO but it is still pending with for very long.