Agreement for sale

The property is in the name of Developer on 7/12 extract.
we made the payment in 2011 i.e 7 years ago. Entire payment was made by cheque. we have a receipt of cash received by the seller/developer .
the plot is in Nashik district , the developers office is in thane District, and purchaser in Mumbai.
Now we wish to exercise our right and want the property to be transferred in our name.

Another option is to sell the property which we cannot do because nothing is in our name .
so the developer has given us a option that he will return the money initially paid to him on execution of few documents and cancellation of Agreement to sale . But the condition is that he will return our money after 3 months of such cancellation.

please guide me