OC for SRA saleable building

Hi, I own a flat in a building built under the SRA scheme in Bhandup. This building is a saleable one ( not the one for the slum owners ). Though the expected date of possession was April 2012, the flat was handed over to me ( and others ) by June 2014. The compound wall is completed only on three sides, while on one side there is a dispute with the adjacent chawl. We have been following up with builder to get the remaining work completed and get us an OC. However, builder says till the adjacent chawl is demolished ( under another SRA scheme or otherwise ), he can't build wall. He says, he is trying to get OC with our consent to the SRA that the wall will be built as and when the chawl is demolished. But, he is unwilling to give a time period for obtaining OC. For the last 2 years, we have been paying our maintenance charges to the builder. Now, he is asking us to take care of the maintenance activities ( without forming a society ). While many of us have paid maintenance charges to him, I have not paid him maintenance charges for last 9 months, as I want him to complete his work first. Now, he threatened to cut off water supply ( commercial connection to the building ) to my flat, if I don't pay maintenance. I will like to get your advice for the way forward. 1. Whether I should pay the remaining maintenance ? 2. Who issue OC for saleable flats in an SRA scheme, BMC or SRA ? I am planning to file an RTI for the status on OC and causes of delay. So need to know which authority to approach. 3. Can the builder cut water supply to my flat ? If he does, what actions I can take against him ? 4. I told the other occupants that even though they wish to take the maintenance activity in their hand, I don't want to be part of it. That also means, till the builder completes his work, I am not going to pay any maintenance charges. Is this ok ?