Legal stand on maintenance charges standalone apartment 75 flats

Sir/Madam, I own a flat in an apartment located at KPHB, Hyderabad, Telangana. It is a stand-alone apartment and around 75 flats with sizes varying from 1200 SFT to 1780 SFT (50 2bhk & 25 3bhk) . We are in the process of forming a CHS. We have prepared an estimate of complete expenses which include common electricity, security, water, Watch, DG & AMC (One time Payment at year-end (2500/- per flat). Now we are having a huge debate on what model to adopt for maintenance charges. We are divided on the below. first-year maintained by Builder on sft basis and after it is decided that should go 2200/- for 2 bhk & 3 Bhk 2600/- for 6 months after that I should be revised as per expenses. now after the meeting, it is changed to sft where 2bhk getting the amount 1600/- & 3bhk-2400/- approx. if equally divided each flat gets 1800/- per flat. some of the people proposed 1900/- & 2400/- to avoid disputes among the owners..few are agreed & some of the flat owners do not agree because if they go by sft they are paying 1600/- & 3 bhk are opposing the proposal. since 3bhk is covering the difference amount of 50 2bhk. since there is not a gated community where there is no amenities to maintain. can I pay only for essential maintenance (Common Power & Water) if I go sft & avoid other services? Please suggest to avoid the burden.