Architect Completion Certificate instea of PMRD Pune Completion C

Hello, Recently I am facing some issue on my Under construction/almost ready property. Below are the details. please guide me on this. I have purchased one flat on Dec,2015 in Pune area and builder promised to give possession on March End 2016 but till the date i could not get the possession even-though the building is 95% complete. Builder is saying that PMRD is delaying to give Completion Certificate. After lots of fight with Builder now a days what they are telling is that they will ask some Architect to visit their construction and based on the Completion Letter from that Architect they will give us the possession. So, my queries are: 1. How much valid that Architect Completion Certificate is compare to Govt Completion Certification ? 2. Should we really take possession based of Architect Completion Certificate ? 3. What all problems we can face if we take possession based on the Architect Certificate ? 4. What all points we can include from builder if we really need to take possession based on Architect Certificate ? 5. What about the govt. Property tax submission in near future for that property ? Regards, Kunal