Rights of heirs of a deceased member in redeveloped building.

I presume that the deceased member had made no nominations, nor had he made a will. The heirs were Associate Members of the society. Are any of the heirs staying in the flat? If not, who is staying in the flat? Under the circumstances the legal heirs will have to get a succession certificate. You get the advice of a lawyer and apply for succession certificate. You also pray to the appropriate court for a stay order on re-development until your issue is settled.

1. No the heirs will not lose their rights on the flat.
2. No. provided you get appropriate court order.
3. If you get stay order, they cannot demolish your flat.

1.The rights of legal heirs cannot be deprived by the society for any reason. 

2. The legal heirs, if are not considred by the develioper and has not been included in the process of redevelopment, then they may obtain a mandatory injunction against the builder to include their names failing which the court can pass a stay order against the redevelopment process.

3. File a petition for stalling the process of redevelopment before the civil court.

4. You can initiate legal actions as suggested in consultation with a local lawyer. 

Multiple legal issues are involved in the facts posted by you despite the fact that an able, competent and intelligent lawyer is engaged / paid by you who has successfully been  protecting interest of LRs of deceased father / member of society.

Neither the Society nor builder can oust the LRs of deceased member from their legal rights, despite the fact that the member did not nominate either of them (LRs) or died intestate, which is not mentioned therein the post.

However, if Society or Builder do not accommodate / recognise  LRs of members in the redevlopment of building, you must obtain stay order from competent court and stall work till then.

The case is stated to be pending before High Court, hence comments on a sub-judiced case without pursuing judicial file shall be futile and may be inappropriate.

Instead of seeking a second opinion on this platform on the basis of limited facts, you should seek advise and guidance of your lawyer, who is well aware about facts and circumstnces of the case, if you have not lost your faith in him/ her.