Terming a common road as private property under what section

Hi. I am from mumbai. The query is regarding a common road with a dead end. To be more precise the road is in between 8 buildings with a dead end. According to the actual plan the colony included 10 buildings in its plan. Now because of some reason only 8 buildings were constructed and at the plot of the remaining 2 buildings there is a chawl where there are almost 120 houses. Now the committee of 8 building without any prior information built a gate like a level crossing and has also denied access for the residents of the chawl. As per the committee they own the road. They donot have any legal documents stating that the road belongs to their colony. Recently BMC has put up a board stating this road belongs to BMC and it would be called with the colony's name. Now the main concern. Can the committee term it as their road, and is it legal to as any details of the cars parked on that road?(according to which section) If they cannot then what is the legal procedure to file a case against their committee? Some of the members are terming it as this is not a public road hence residents of the chawl needs to park their vehicle somewhere else. What is the procedure to term a road private? Is it possible to term a road private without courts legal order? If done so is it violation of law?