Payment of Society Fees in Residential Apartment

We had entered into an agreement with a builder in 2011 to construct a residential apartment(non-commercial) comprising of 12 units and 2 flats were allotted to us. The same has been completed but the society has not yet been formed as the builder is yet to produce NOC and Occupancy Certificate, but all flats have been sold and occupied. How or can the society be formed at this stage or are the flat owners liable to pay society/ maintenance charges till the builder produces all documents and a society is formed? In our case, a fixed sum has been collected on a per flat basis and so we are paying for two units since last three years. We are not living there in the flat since last three years but outstation due to my job and one flat is let out.Now the society proposes to increase the monthly charges and we will have to pay approx 3000/- more in that case. Can we pay for one unit only or for one unit only plus say 800/- for the other flat and not 1500/- as we are not utilising the common facilities? Is there any relief for the landlord in this regard and how the builder be made responsible to get required certificates, form the society and bearing the monthly maintenance charges till formation of society? In our state of Assam, I believe there are till now no concrete rules governing residential apartments or societies formation,