Revocation of registration extended for taxpayers served by electronic notice to apply within a prescribed extended period. A temporary proviso permits registered persons whose registrations were cancelled and who were served the cancellation notice electronically by e-mail or via the common portal to file applications for revocation despite the expiry of the ordinary revocation and appeal periods; relief is limited to cancellation orders up to a specified cutoff and grants an extended deadline for eligible applicants, invoked under the executive power to remove difficulties arising from unfamiliarity with electronic service.