The Additional Registrar of Co-operative Societies (ARCS) has power under Section 70 to:
examine legality of allotments, cancel allotments and even registered sale deeds, if they are contrary to sanctioned plans, bye-laws, or statutory requirements.
This includes illegal conversion of parks / civic amenity areas, allotment to bogus or ineligible members and manipulation of land details and site numbers, and also that the registration of a sale deed does NOT protect an illegal transaction.
You can make a complaint to the (BDA / BMRDA / Local Authority) for violation of sanctioned plan and Park encroachment.
You may consult an advocate having expertise in the field and proceed as advised.
