Plotted development

Though the JDA was executed by an unregistered document but the POA was executed by a registered document giving powers to the developer  to sell the property.

If the karab land was not part of the JDA then you can issue a legal noice to the developer for violating the agreement conditions and instruct him to refrain from going ahead, if he is not listening then you can file a suit for cancelaltion of the JDA, POA  and to restrain the developer from alienation or further encumbrance of the properties. 

The POA is not done. He is asking us to regsiter the property directly. Without knowing all these things my dad already registered few plots. That's my concern now. 

Without POA on his name the developer cannot sell the property including his share in the property that has been developed.

If the karab land is also part of the joint development agreement then the developer has to sell them through the landowner only.

Actually you have not disucussed the actual problem, therefore your doubts can be clarified by an experienced lawyer in the local after perusing all the documents, otherwise you can approach any lawyer of this forum with all the relevant papers in order to get all the issues properly clarified. 

Review all rules and regulations set by your local developmental authority for drift hunters that region. There are often specific guidelines around plot sizes, setbacks, floor space index limits, etc.