Sold 51% of a wing? The three-month clock for a builder to apply for your housing society

Rules as of 13 October 2026.

Two questions about housing societies and RERA often get mixed up. One: once enough flats are sold in a new project, when must the builder start the society? Two: when a society redevelops its own plot, does it become a "promoter" with a builder's liabilities? This explainer takes both, with the exact rule and the court rulings I could read. It is general information, not legal advice.

The 51% clock in Maharashtra

The Act itself says little. Section 11(4)(e) makes it the promoter's duty to enable the formation of an association or society or co-operative society of the allottees, or a federation, under the applicable laws. The proviso adds that, in the absence of local laws, the association must be formed within three months of "the majority of allottees" having booked in the project. "Majority" has no number in the Act.

The number comes from the Maharashtra rules framed under RERA. As quoted by the Bombay High Court in Gera Development v State of Maharashtra (1 April 2026), Rule 9(1) says:

• (i) where a co-operative housing society, company or other legal entity of allottees is to be formed, the promoter must apply within three months from the date on which fifty-one per cent of the total number of allottees in the building or wing have booked their apartment;
• (ii) where an apex body (a federation of separate societies) is to be formed, the application is due within three months of receiving the occupancy certificate;
• (iii) if the promoter fails, the Authority shall by order direct him to apply, or may authorise the allottees to apply.

The clock is per building or wing, not for the whole layout. For a wing of 60 flats, 51% is 30.6, so the 31st booking starts the three-month period.

What the High Court said in Gera

The court (Justice Amit Borkar) upheld the Minister of Co-operation's order that had restored the District Deputy Registrar's registration orders. It held that the promoter has no discretion on timing, and that "mere readiness" with documents kept ready for signature does not keep the promoter's right alive. When the promoter fails to act in time, the right to proceed shifts to the purchasers, who need not keep waiting. In that case 109 of 155 existing unit holders supported forming one society, which the court said crossed the 51% mark. On whether each tower needs its own society, the court said Rule 9 does not require a separate society for each tower in every case; the layout, shared facilities, agreements and conduct matter.

Older Maharashtra law also has a duty. Section 10 of the Maharashtra Ownership Flats Act requires the promoter to apply to the Registrar within the prescribed period once the minimum number of persons needed to form a society have taken flats, and Rule 8 of the MOFA rules fixes four months for that. Whether MOFA survives next to RERA is debated, but the High Court applied section 10 in Dilip Bobde Patil v Laksons India (14 October 2025) and quoted it in Gera. In the October 2025 case the court restored a registration where seven of ten purchasers in a building had signed.

Why the society matters to you

The association is the body that is to receive the common areas under section 11(4)(f) and section 17, and it has a role if a project is abandoned: the proviso to section 8 gives the association of allottees the first right of refusal to carry out the remaining development work. Section 15 stops a promoter from transferring majority rights without the written consent of two-thirds of the allottees and the Authority's approval, and section 14(2) needs the written consent of at least two-thirds of allottees for changes to sanctioned plans or common areas. An organised group of buyers is what those numbers need.

When a society becomes a "promoter"

Section 2(zk)(iv) of the Act defines a promoter to include a primary co-operative housing society which constructs apartments or buildings for its members or in respect of the allottees of such apartments or buildings. That is the statutory hook. On facts, reports say courts look at the society's role and stake:

• A report by LiveLaw (4 January 2025) says MahaREAT held that a society owning the land and authorising a developer to redevelop it falls within the definition.
• A Mondaq report on a Bombay High Court order of 8 April 2026 in Shri Sai Vishram CHS v Ninad Paralkar says the status is not automatic: a society that only allows redevelopment in exchange for flats for its own members may not qualify, but one entitled to 50% of the built area and a Rs 3 crore corpus fund was a promoter. I have not read the order itself.

In Wadhwa Group v Vijay Choksi (Bombay High Court, 26 February 2024) the court held that a registered promoter that shares in sales cannot escape section 18 refund liability merely because the buyer paid someone else. If a society is a promoter, the same logic can reach it. Our separate note on rehab and sale components explains the split.

A worked example

Illustrative: a new wing has 60 flats. The 31st buyer books on 10 March. The promoter must apply for the society's registration by 10 June. If he does nothing, the buyers, with a list of 31 or more signatories, can ask the Authority under Rule 9(1)(iii) to authorise them to apply. Gera suggests the courts will not make them wait.

Mistakes to avoid

• Waiting for the occupancy certificate to start the process. The 51% trigger is earlier.
• Counting the whole layout instead of the building or wing.
• Not keeping a dated list of bookings and signatories.
• Assuming a society redeveloping its plot is automatically a promoter; check the agreement and the share it receives.