Extension of time-limit for revocation of cancellation of registration extended to September 30, 2021; further extensions conditional. Where due date to apply for revocation of cancellation falls between March 1, 2020 and August 31, 2021, the filing deadline is extended to September 30, 2021 for registrations cancelled under clause (b) or clause (c); this extension applies regardless of application status (not filed, pending, rejected, on appeal, or rejected on appeal), and officers and appellate authorities must process or decide applications taking the extension into account. The circular further clarifies how administrative 30+30 day extensions under the proviso interact with this extension based on whether 30, 60 or 90 days had elapsed by August 31, 2021.