what legal action to be taken against builder?

I had purchased a 2 BHK apartment and one covered parking area in a housing complex of north kolkata on December 2009. Sale agreement completed on January 2010 and I completed payment as per scheduled demands. I started to reside in the apartment since December 2011 and started to park my personal car in a temporary parking area of the same premises since January 2011. The land of the complex was a government land and it was given on a lease of 99 years to the builder. The project was partailly completed and partially ongoing throught the years. The registration of the of the apartments were deferred and as of now it has been decided to be done by next two months. Recently , the builder started to mark the parking lots for each vehicle and it was observed that they alloted more parking areas than planned ( I never saw the plan for parking area before). As a result the parking spaces look clumsy, smaller in area and difficult to park vehicles due to obstacles and dependency with other vehicles. They verbally said that the parking spaces will be allocated by lottery. My question is, what kind of legal action I can take against them if I find my parking space is not satisfactory after lottery.