Sale deed - confirming party legal heirs

My father had purchased and acquiuired a chaal in 1968, which is umregistered. He expired in 2016, without leaving behind any Will. As per his wish he had nominated me as his nominee for his 100% share and ownership in the said flat after his demise. Accordingly, I submitted the application to society for transfer of the said flat and membership rights of the society and also had obtained notarized Affidavit from other legal heirs stating they never had any right, title or interest during my father’s life time and after his death. The society which was formed later on had admitted me as a member of the society and endorse my name in the Share Certificate. Then in late 2016, we entered in redevelopment registered agreement with buillder having my name as owner. So post development n possession, i entered into registered agreement for sale in mar 2019. Question - is this agreement is legal Or 1. Do I need to provide latest Affidavit – No Claim Declaration from other legal heirs? If yes, Notarized or registered? 2. Should all legal heirs be the confirming parties to the current agreementagreement/sale deed?