Neighbours parking their car in my space

I have a property in Chennai Saligramam I own a flat of 1100 sqft and 19.1% of UDS of total sqft of 3189 At the time of Construction there was no earmarked space for car parking In our apt total 5 Occupants and on top builder office and one house both in the name of the builder There is car parking space for four cars when I was in Chennai I used to park my car in that area but now since I moved out of Chennai one of the owners bought a car and parked in that space Few years before the builder had drawn a line for bike park for each flat but now they are saying that its their car park and no body is moving their car and now since my car is in kochi they are saying that I don't have car park because of the line everybody is parking in that area I own the biggest flat in terms of sqft and UDS Now I am not able to sell my property because I don't have a carparking space Please advise