Revocation of GST registration: limited window to apply after cancellation, subject to filing returns and paying tax, interest and penalties. Permits persons whose GST registration was cancelled under the statutory cancellation clauses and who failed to apply for revocation within the ordinary time limit to apply for revocation by the specified final date, provided they first furnish all returns due up to the effective date of cancellation and pay any tax due under those returns together with interest, penalty and late fee; no further extension is available, and the class includes those whose appeals were rejected for failure to meet the time limit.