Every supplier whose aggregate turnover exceeds Rs. 20 Lacs (10 Lacs for special category states) in a financial year is liable to get himself registered in a State from where he makes taxable supplies. However, certain categories of persons mentioned in Section 24 of GST Law are liable to be registered irrespective of this threshold. Further, following persons shall not be liable to register as per section 23: –
(a) An agriculturist, to the extent of supply of produce out of cultivation of land.
(b) Any person engaged exclusively in the business of supplying goods and/ services that are not liable to tax or wholly exempt from tax under the CGST Act or under IGST Act.
(ICAI FAQ PUBLICATIONS 06-09-2017 REGISTRATION: FAQ NO. 16)