Turnover limit for RCM supplier

Not required to register as per Section 23(a) any person engaged exclusively in the business of supplying goods or
services or both that are not liable to tax or wholly exempt from tax under this Act or under the Integrated Goods and Services Tax Act;

The answer that registration is not required will remain same as given above but the correct reference will be Section 23 (2) read with notification 5/2017