Section 24 CGST Act

Notwithstanding anything contained in sub-section (1) of section 22, the following categories of persons shall be required to be registered under this Act,––
(i) persons making any inter-State taxable supply;
(ii) casual taxable persons making taxable supply;
(iii) persons who are required to pay tax under reverse charge;
(iv) person who are required to pay tax under sub-section (5) of section 9; (v) non-resident taxable persons making taxable supply;
(vi) persons who are required to deduct tax under section 51, whether or not separately registered under this Act;
(vii) persons who make taxable supply of goods or services or both on behalf of other taxable persons whether as an agent or otherwise;(viii) Input Service Distributor, whether or not separately registered under this Act;
(ix) persons who supply goods or services or both, other than supplies specified under sub-section (5) of section 9, through such electronic commerce operator who is required to collect tax at source under section 52;
(x) every electronic commerce operator;
(xi) every person supplying online information and database access or retrieval services from a place outside India to a person in India, other than a registered person; and
(xii) such other person or class of persons as may be notified by the Government on the recommendations of the Council.