Delhi Development Authority [DDA] — encroachment of common property

Address: 110063

I have a flat in nav bharat apt block a4 paschim vihar delhi 110063 since 2003. Every year people on ground floor are increasing the encroachment of common property.
The area for their private sittings & exclusive use keep increasing with simultaneous decrease in area for common parking & garden. We request you to enforce the society by-laws as our executive committee has failed miserably to act in common interest.