Revocation of registration cancellation time limit extension under Assam GST requires sufficient cause and recorded reasons. Extension of the time limit for applying for revocation of cancellation of registration under the Assam GST framework is to be handled through a uniform procedure until GSTN functionality for FORM GST REG-21 is available. A registered person may seek extension by letter or e-mail after 30 days but within 60 days, and a similar procedure applies where the request is made after 60 days but within 90 days. The Joint or Additional Commissioner may extend the time limit on sufficient cause being shown and reasons recorded in writing.