Apartment-maintenance Related

Hi Sir/Madam, We are currently staying in Hyderabad. Our apartment consists of 35 flats where 20 2-BHK flats of size 1120 sq. ft and 10 3-BHK flats of size 1610 sq. ft and 5 flats of size 1560 sq. ft. We recently proposed all owners to pay the common maintenance and expenses based on the size of the flat or the undivided share being held by each owner. Even there was a conflict with 3 BHK owners demanding us to pay equally for all the flats in the apartment. Recently we got a Manjeera Connection estimation which is based on the entire 1851 sq. yds or 1548 sq. meters. We proposed collecting the amount based upon the undivided share being held by each owner of the flat to which all the 2-BHKS flat owners agreed. The 3-BHK owners are against this. We are seeing conflicts between below issues: 1. Common Expenses and Maintenance of the apartment. 2. Manjeera Connection Expenses Can U suggest Who's Version Have valid? 2bhks OR 3 Bhks Thanks.