Property tax bill even though possession not taken

Dear Sir, I have not taken possession of the booked flat because the builder has not received OC as yet. But the Mira Bhayandar Municipal Corporation has sent a Property Tax bill in my name. So, what should I do ? File a case in MahaRERA ? or file a complaint in MBMC ? In MahaRERA can I make builder and MBMC both parties to the complaint ? Thanks, Deepak.