Municipal Corporation Of Delhi — construction on roof

Address:

A-76 ground floor fateh nagar, New Delhi, Delhi, 110018

I stay in the ground floor fateh nagar. We have 2 bed rooms in 75 gajj of land. I have my elder bloor which are already married and my marriage are already fixed so due to short of place we need to construct a floor on the roof which is in my father's name.
We recieved NOC from the owner of first floor but owner of second floor are not taking any interest in giving NOC to me. Under this circumstances i need your help without which i will not be able to construct my floor on the roof.