Due to ongoing Coronavirus, the Ministry of Finance has extended the due date for filing of GSTR 3B to April 7, 2020. A statement released by the CBIC mentions that it has been decided to “extend the due date of filing the annual return in FORM GSTR-9 and reconciliation statement for financial year 2018-19 from March 31 to June 30, 2020”. The date for composition has also been extended to April 7 from March 31.
https://www.cnbctv18.com/finance/covid-19-deadlines-for-filing-gst-returns-extended-5540151.htm