Extension of time to apply for revocation of cancellation of registration allows administrative officers to grant limited extensions upon sufficient cause. A delegated extension regime allows the Joint/Additional Commissioner to grant an initial extension and the Commissioner a further extension where sufficient cause is shown and reasons are recorded; until GSTN portal functionality exists, applicants who apply belatedly must request extension through the proper officer, who forwards it for decision; decisions, hearings and communications follow the prescribed interim procedure, and the circular ceases once portal functionality is available.