Delay compensation for a RERA Registered Project

I invested in a property in Pune in August 2018. The project had begun in pre RERA days and had promised some of it's existing buyers completion date of Dec 2016 which it clearly didn't meet. At that time when my agreement was executed ,project was registered with MahaRERA and had a completion date of 31 December 2018. My agreement has a completion date of December 2018 too. They have failed to deliver the flats till now (September 2019) with a lot of construction still to be done. In December 2018 they applied for 1 year extension in RERA and got completion date extended to Dec 2019. Their RERA application currently shows this: Proposed Date of Completion:31/12/2016 Revised Proposed Date of Completion: 31/12/2018 Extended Date of Completion: 31/12/2019 Will I be able to seek damages from builder as he has denied any for Dec 2018 - Dec 2019 period arguing that RERA extension overrides all previous agreements. Will I at least be able get compensation post Dec 2019 or can he extend.