Forming a society without OC and municipal water supply

I purchased a flat from builder in Dec 2018 (District Palghar, Maharashtra) by taking home loan, 80% of my flat. We were amongst initial occupants. Total saleable flats are 154. We were told while booking a flat, in Nov 2018, that in 4 months time OC and municipal water would be available and thus they gave us fit out letter and made us allowed to occupy the flat in Dec 2018. Till now that is June 2020, we have not received OC and thus we are deprived of municipal water. Due to this builder is providing us tanker water and that cost him around Rs 2.30 lac per month which he collects from us through maintenance charge. Due to this our maintenance charges comes to around Rs 6 (including GST) pm which is huge as compare to Rs. 3( without GST)on maximum side in our region. In month of April this year, builder said that from May onwards he would not maintain the society and asked us to manage the collection of funds from flat owners and manage the expenses of our own to maintain the society. Expenses mainly include water tanker charges, electricity bill, security and hose keeping. So 11 members on the basis of consensus took initiative to manage the activity. Now builder is proposing us to take over the society formally. Need guidance to know the if we can take over the society formally without OC. Builder has given us in writing that obtaining OC and municipal water is solely his responsibility. As understood from some regional legal advisor, most of the projects in our region are occupied by owners despite non receipt of OC.Also guide on this.