As of now the due date to file Annual Return ( FORM GSTR-9 ) for FY 2019-20 is 31st December 2020. But it will surely get extended since the due date to file FORM GSTR-9 for FY 2018-19 is also 31st December 2020.
As per the Provision of Section 44 of the CGST Act 2017, the due date to file Annual Return is 31st December of the following financial year.