Bogus gift deed based on wrongly obtained MMDA approval

1) One prevailing, MMDA approved layout plan was obtained based on false documents in about 1984. The right of the person (who obtained that approval wrongly) over the land involved, was declared null and invalid, in three judgments (two appeals) attaining finality in 1994 in Madras High Court. 2) The history being: a) 'A' was given Power of Attorney by 'B' over a parcel of land in about 1980. It was Agency coupled with Interest. A's buyer entered into an agreement to acquire the property then. b) Subsequently, 'B', by filing false documents got a bogus approval from the MMDA and began selling the land as plots. c) 'A' moved the court and got an interim order restraining 'B' from indulging in such an activity. d) The case was decided in A's favor. An appeal and again another in higher courts were also decided in A's favor. It seemed sufficient then against any illegal activity. e) Meanwhile, B had marked an area in the wrongly approved plan as a public park site and had made over a gift deed to the corporation in about 1986, without having any valid right to do so, which is giving cause for the local welfare association to raise a claim on A's purchaser's property - which is involved. f) Now there is a new litigation in court where the Corporation is also a party because of the local welfare association's claim. g) The land has been in the possession of A's buyer unhindered for 37 years now. 1) How to cancel the false MMDA plan and nullify the mischievous gift deed? 2) Should the suit be to cancel the bogus approved plan, or to deny the legitimacy of the act of approving itself of the plan; which of these is appropriate - can be expected and sought as relief? 3) Which is the appropriate forum or court? 4) Is a writ petition applicable? 5) Is there a limitation (time bar) involved in approaching the court for canceling the bogus MMDA plan? (The MMDA’s wrong approval was given during the existence of the interim injunction against ‘B’) 6) How to approach this issue? How should A's buyer establish his ownership right on his portion of purchased land, conclusively, against the wrongly obtained approval and the ensuing false gift deed.