Yes... It's can be file on or before 30th Jun-2020. Refer notification no 33/2020 CT it's for waiver of late fee & penalties. So, It's considered to extend the due date to 30th Jun-2020...
Due Date for filing FORM GSTR -1 for the month of March, April and May 2020 stands extended to 30.06.2020. Late Fees levied under Section 47 of the CGST Act 2017 is also waived, provided that the Statement is filed on or before 30.06.2020.
Refer Notification No. 33/2020 - Central Tax, dated 03.04.2020, for official correspondence.