Compulsory GST registration required for specified categories including inter-state suppliers, casual, non-resident and e-commerce operators. The provision establishes compulsory registration under the Assam GST Act for specified categories irrespective of the general threshold rule, tying registration to the nature of supplies or statutory obligations. Specified categories include inter State suppliers, casual and non resident taxable persons, persons liable under reverse charge, persons required to pay tax under intra statute charging provisions, tax deductors, agents supplying on behalf of other taxable persons, Input Service Distributors, electronic commerce operators, and suppliers of online information and database services from outside India to unregistered persons; additional classes may be notified by Government.