Regarding registered development agreement

If the legal heir's of the late Developer, willing to continue the  development works, as per the terms and conditions made in the Development Agreement, only a Supplementary Deed can be executed by the Land Owner and the Legal Heirs. The registration of the said Supplementary Deed, is depending upon the interest of the parties. 

Dear B Subrahmanyam Ji,
 

First of all thank you for your reply. Sir , as per your reply posted today 

• if the land owner is not ready for supplementary deed than ?
• If the late developer had already paid the money to the land owner the cost of land discussed between them then also it is necessary to make supplementary deed ?
• Also the land owner has agreed that he has received all the money and he has transfered all his rights to the late developer in the registered agreement.
• Now the land owner had called the legal heirs of the late developer and he has offered them a proposal in money ? What action should we take ?

Please suggest or is there any other way ?

Sanjeev Kumbhar