Parking issues in Small Residential omplexes with 6 flats

I am an owner of a three bedroom flat in a small Residential Complex having 6 flats. As per the Builders' Design and approved by Chennai Corporation, the Stilt Plan has indicates the length of my car Park slot as 750 cm.(25 ft.) and breadth as 250 cm. 8.33 cm.). I have two small cars, the added length of both the cars put together is 24 ft. I am parking both the cars in the Parking Slot alloted to my flat as per the Chennai Corporation Approved plan of the Stilt of my Complex?. There is no registered Association for us, as there are only 6 flats (less than 7) and purchased in 2004. Unofficially, all the owners maintaining a Building fund to which every owner is contributing maintenance charges. The accounts are maintained by one of the owners every three months on rotation basis. Now, suddenly the other owners are demanding that I should be separate parking fee for my second car, though both my cars are parked within the space marked for my slot as per approved stilt plan. I find in many small complexes like this, if space is available in the allotted slot, one car and also some two wheelers are parked, and no- one objects or demands extra parking fees?. Please let me know whether the demand made by other owners is legally correct, and is there any prohibition in the Chennai Corporation Apartment Rules/Regulations that in Parking area, only one car should be parked even if there is enough space for parking another small car?. Will be thankful if I am guided on this.