Ownership of parking space in ground floor owner

My brother had built a house in 1980 consisting ground floor, first and half portion of second floor half in Bangalore nearby Hosakerehalli village on a independent plot measuring 60 x 72ft. He sold his first and second floor portion of the said house to a tenant of same house sale consideration in 2000. the Purchaser had mentioned that car parking area belonging to ground floor portic0 as "reserved car Park" for parking first floor purchaser and all common areas in and around the house maintenable by occupants including ground floor owner, and purchaser of first and second floor. He has also mentioned in the sale deed that further portion of second floor house extension can be built by purchaser and both owner and purchaser has no right to build any construction upon second floor roof top.Separate BBMP khata has been bifurcated and separate tax payment ibeing made by Ground Floor Owner (ie. my brother) and first and second floor purchaser. Now that my brother would like to move away from Bangalore to settle down with his children in UK, he intends to sell the ground floor portion of his to a third party. However, the first purchaser is obstructing for sale and not allowing to park the car in the portico belonging to my brother. Is there any any to restrict the first purchaser (first floor and second floor as they have separate stair case and not contributing to maintenance of the bjuilding in any way) not to interfer in sale of ground floor and obstruct for parking space. Parking space is not offered on slae consideration. Kindly advise.steps involved in this regard. ramachandra rao