Parking issue in south delhi

We are and have always been the owner of original land in GK Enclave-2 (lease hold property) our father sold the upper 2-floors to builder some 15yrs ago, who built 4-aprtments and sold them, new owners are parking in front of the house, we made a gate on our side of the ground floor (which used to be there before builder modified)he put a middle gate for access to upstairs owners and closed left and right side gates,-such that we 2-brothers have 2-ground floor apartments. We were out of the country at that time, so didn't bother-but now living there-so need to make a gate and have access to parking since street parking problem due to other apartments in the building. While my mother still lives with us, father passed a way a few yrs ago. What is our right to making a gate to park inside the ground floor area., and having to make a ramp to park car inside -so the ease of access to drive-in.,upstairs people have issue with that-street parking space is city land-they will park their car infront of ur gate (on a first come first serve basis) how do we handle this please suggest-Many thanks (im presently abroad-while my brother is in delhi)-I suggest its best to communicate with email as preferred mode of communication due to time difference-thanks a ton