Maharera and builders

Big Residential Project which is started before Maharera showing a complete one project ,now Project has been divided with phase no. to get different Maharera No. with each phase completion date is differ from other phase. And now last phase made within project having completion date on rera website is after 4-5 years later. Now even though builder make some buildings ready to stay ,amenities ,gardening,etc will be delayed showing last phase completion date which comes after 4-5 yrs late. what action we can take or cant take any action i this case .