Ownership of propotionate land & its use in Delhi Builders Floor

220 yard Land owner residing in two top floors, who had build up 8 flats on it. He has sold out in registery 3 flats on each 100yards plot where as stair case are commonly build for both the plots. On one plot he has made a office of property dealer on half of the space. Whereas on another side of plot he has made a room being used by Guard on his mercy. Due to less space on one plot only 3 cars can accommodate in that plot and he put one car on another side of plot parking. He always argue with flat owners that land belongs to him and he has allowed to keep one car only not scooter or other things to keep in parking. Since he is illiterate person so we dont argue much with him. He has mentioned in the registry that at one side some space has been left for owners use but not mentioned in registry for what purpose and he is using as property dealer office. 1-Can we show him any rule on Delhi Builder's flat ownership act 1986 that all owners of flats will decide the use of parking area, what to keep and what not. 2-He has roof rights and willing to construct rooms over top floor where our water tanks are located. If he does that it will worsen our parking are more as he may give on rent to others, how we can stop him to do so. 3-He has not done registry of his flat being self owner of plot, should I make complaint to Registrar office so he has to pay the registry charges and house tax etc or it is not applicable in his case being owner of plot earlier. 4-How we can demolish the space being used on another plot for property dealer office which is obstructing the space for parking. Is there any Supreme court or law guidelines about it. 5-Can we the owner of flats of our plot can deny to park vehicles of other side of plot flat owners on my side in case both plot has common stair case. 6-Where we should complaint about it for legal action without going to litigation.