Responsibility of Builder & Land Owners for paying Uniform Maintenance Charges For Unsold Flats

Ours is 184 apartment Complex in Bangalore. A Block 72 flats. B Block 112 flats. RWA not registered yet because of faulty UDS, which is being corrected now. DOD is getting ready. 50% of the apartments are owned by the Land Owners. They have sold only 5 apartments in the past 4 years as they are waiting for better rates. They have divided the flats within 5 family members. We have fixed Rs 3/ sft as maintenance charges. They have occupied some flats and rented some flats ( about 12). In A Block, which was finished first, they have reduced the maintenance to Re1/sft for unoccupied and in sold property. In B Block they are not paying anything for maintenance of 53 apartments, under the excuse that the builder has not completed the project, even though builder has got partial OC. 40 apartment owners are living there of which 3 are their tenants. We are in funds crisis for payment of service providers, BESCOM, BWSSB etc. They refuse to attend meetings or come to our help. Builder is playing the same game for his share of the unsold properties. Please advice.