Revocation of registration cancellation allowed subject to filing outstanding returns and payment of all dues within a limited window. Registered persons whose registration was cancelled under clause (b) or clause (c) of Section 29 on or before 31st December, 2022 and who failed to apply for revocation within the Section 30 time limit may apply for revocation up to 30th June, 2023 only after furnishing returns due up to the effective date of cancellation and paying tax, interest, penalty and late fee; no further extension is available, and the category includes appeals dismissed for time bar under Section 30(1).