Release deed

If your sister executed a registered release deed in your favor then you need not give any indemnity bond, just fill up the membership transfer form and comply with the requirements as stipulated in the bylaws in this regard.

If the society is still insisting on any illegal equirement then you can approach the deputy registrar to get your grievances redressed and a direction to the society to do the needful 

The society cannot seek indemnity bond when you have submitted copy of registered relinquish deed, when you are co-sharer  in the property with your sister devolved in succession.

Yes.  I agree with the view of the above learned experts.

Once the release deed has been executed and registered, it is unnecessary that the indemnity bond be provided.

It is an established law that the RELINQUISHMENT DEED (Subject to, that it is REGISTERED one) is enough to release a co-owner's share from the property. No further Indemnity Bond or any types of NOC is further required to establish this as per legal process. The society MC must verify  follow this.