Builder is not providing OC and Khata A

Hi, I am the second owner of a flat in Bangalore and i came to know from fellow residents that the builder is not providing the following documents: 1. Occupancy certificate 2. Khata A for individual flats This is a 100+ apartment society situated on a land having Khata A. Builder got the approved plan for 2 towers from BBMP but the final building contains some deviation from the original plan. Builder claims that they have applied for "Akrama Sakrama" for the deviated portion and waiting for the approval from the concerned authorities. This society plan was approved by BDA in 2008 and it was constructed and registered to individual owners in 2012. Since 2012 resident welfare society and residents are staying in more then 100 apartments. Now Resident owners welfare association want all the legal documents like OC, Khata "A" in their respective name but builder is not providing the same. There are lots of work pending like Rain water harvesting, BWSSB and Kavary water supply connections as the concerned authorities(BWSSB) are saying that they have not received the fees from the builder for the designated connection. Residents have paid an additional Rs 125 per square feet for BWSSB/BESCOM and other authorities fees back in 2012 to the builder vide their agreement/sale deed while doing the apartment registration in BBMP. Please suggest what an "owner/ Socity owners association" should do to get all these things completed and obtain OC and khata A in their names?