Validity of Unregistered Development Agreement cum GPA

What is the validity of a DAGPA entered between Developer and 100 plot owners individually with the developer where: 1. It is unregistered 2. The developer has paid refundable advances to the plot owners 3. The project is held up at the clearance and permission stage and there are still some plot owners among this 100 whose plots do not have a clear marketable title. 4. The unregistered deed mentions construction period of 3 years and penalty thereafter but does not mention periodicity for cancellation of the agreement/GPA if project does not take off 5. Can we presume that it stands automatically cancelled after 3 years validity period of unregistered documents? 6. If in Force Majure clause 'Government Regulations' are mentioned and due to which if the project has been inordinately delayed for more than 3 years, can the developer be held responsible, can the plot owner dump the developer without cancellation of this unregistered document as consideration has been paid by developer in the form of advances ?