Whether the cancellation of registration certificate is permissible

Yes. Any Registration granted under this Act may be cancelled by the Proper Officer, in circumstances mentioned in Section 29 of the CGST Act. Also, the proper officer may, either on his own motion or on an application filed by the registered taxable person or by his legal heirs, in case of death of such person, cancel the registration.

(ICAI FAQ PUBLICATIONS 06-09-2017 REGISTRATION: FAQ NO. 25)

Whether Amendments to the Registration Certificate is permissible

Yes. In terms of Section 28, the proper officer may, on the basis of such information furnished either by the registrant or as ascertained by him, approve or reject amendments in the registration. The application shall be made within 15 days of such change. It is to be noted that permission of the proper officer for making amendments will be required for only certain core fields of information, whereas for the other fields, the registrant can himself carry out the amendments.

(ICAI FAQ PUBLICATIONS 06-09-2017 REGISTRATION: FAQ NO. 24)