Where an application for grant of registration certificate is furnished under rule 11-A and the Commissioner either has not granted the certificate of registration or has not rejected the application for registration within the time specified in sub-section (4-A) of section 17, the application for registration shall be deemed approved and the certificate of registration shall be deemed granted by the Commissioner. The certificate of registration, deemed granted under this rule or granted under rule 12, as the case may be, shall be system generated through the official web portal of the department with or without digital signature of the Commissioner and shall be downloadable at the applicant's end.