Extension of GSTR-3B filing for newly migrated taxpayers imposes an electronic submission deadline through the common portal. Extension of the electronic filing deadline for FORM GSTR-3B is mandated for taxpayers who newly obtained GSTIN under the specified migration notification; the Commissioner amends two prior state notifications to insert a proviso requiring that returns in FORM GSTR-3B for the covered period by these taxpayers be furnished electronically through the common portal by the revised deadline, with the amendment declared effective from the stated commencement date.