Aadhaar authentication requirement for GST registration eligibility from effective date, alternate identification accepted when Aadhaar unavailable. Notification fixes the date from which an individual must undergo Aadhaar authentication as specified in the GST rules to be eligible for registration; if an Aadhaar number is not assigned, the individual shall be offered alternate and viable means of identification as specified in the rules. The notification declares that it shall be deemed effective from the stated effective date, thereby commencing the authentication requirement and alternate identification provision.