The registered person shall furnish an explanation for the discrepancy in
FORM GST ASMT-11 to the proper officer within such time, not exceeding thirty days from the date of service of the notice or such further period as may be permitted by the proper officer. Where the explanation furnished by the registered person or the information submitted thereby is found to be acceptable, the proper officer shall inform him accordingly in FORM GST ASMT-12.
(ICAI FAQ PUBLICATIONS 06-09-2017 SCRUTINY OF RETURNS: FAQ NO. 16)