When builder can start charging society maintenance charges ?

My Residential complex is in PMC limit, Pune and has a total of 149 apartments in 3 blocks. The builder has handed over 70% of the flats and 30% of the flats have been occupied by now. The complex has electricity supply from MAHADISCOM, water, lifts, security and common area cleaning provided as of now. But, the following are yet to be completed by the builder: (a) All amenities are pending – Club House, Parking, Children's play area (b) Required NOCs not received (c) OC & CC not received (d) Final coat of paining in all common areas pending. The builder had promised a delivery date of June-2019 with a grace period of 3 months, which ended in September 2019. Builder has given only flat hand over letter and not yet given building completion or possession letter. Electricity was made available after which owners started moving in due to practical necessity and the builder claiming that the complex is ready for occupation. Now, the builder is asking the owners to start paying maintenance fee from the day residents received flat handover letter to cover day to day expenses like security, housekeeping staff, electricity in common areas, diesel etc. There is no clause of the builders maintaining the apartment for the first "x" months in the sale or construction agreement. My question is whether the builder can demand maintenance fee for the items I have mentioned above, while the complex is not fully completed (mainly amenities remaining) and without possession leeter/OC/NOC being obtained. I understand that we should not have occupied without getting an completion certification and possession letter from municipal corporation, but there are practical issues like rent vs. load, notice given in existing apartment etc. that forced people to move in. Appreciate your help with this.