Extension of final return filing deadline for cancelled registrations allows submission of FORM GSTR-10 after cancellation. Notifies an extension permitting persons whose GST registration was cancelled on or before 30th September, 2018 to furnish the final return in FORM GSTR-10 by 31st December, 2018, issued under section 148 read with section 45 and rule 81 of the Sikkim GST Act and Rules.