Does a non-resident owner in a Bangalore Apartment needs to pay Maintenance Fee

I am working as Secretary of a Resident Welfare association of a housing society registered under THE KARNATAKA SOCIETIES REGISTRATION ACT - 1960. Our monthly maintenance charge comprises of BESCOM, DG, BWSSB, Security, Repair and maintenance of amenities and infra, HouseKeeping/Cleaning and PAID WATER. At inception in 2011, the maintenance fee decided to be on Fixed Scheme (i.e. not on square feet basis) though there was PAID WATER COMPONENT which would be used wherever no of residents more. For example, for all 2 BHK (area might vary little bit) - Rs 2400 and for all 3 BHK - Rs 2800. It was decided that all ways the difference between 2 and 3 BHK should be maintained as Rs 400 (due to PAID WATER component - as generally assumed that 3BHK has more space to accommodate more people). Well, at this same point, also it was decided that for non-occupied flats, fixed maintenance charge would be Rs 1000. In last 9 years, the maintenance fee for all occupied flats has increased up to say Rs. 3700 (for all 2BHK) and Rs 4100 (for all 3 BHK). Now when we are trying to increase maintenance fee for the vacant flats, there are challenges observed with generic argument that "no service used, why we should pay". Question : What components (described above which comprises our maintenance) can be waived for vacate flats as fair practice ? Second, is there any binding law (apart from our own bye-laws) that even non-occupied flat owners have to pay the "maintenance fee" and even service fees which they are not consuming ( e.g. Electricity to light up common area and run water pump or lift, Diesel for back up power, Security or cleaning services etc.). Apart from binding law, is there any Govt guideline on this subject topic that what all components of Maintenance fee can be charged to a non-occupied flat owners ? Disclaimer: All the figures given above are fictitous and only for illustrative purpose.