Compulsory Registration under GST

A person needs to get registered under GST if :

1). His Aggregate Turnover exceeds Rs. 40 lakhs incase of Exclusive Supply of Goods.

2). His Aggregate Turnover exceeds Rs 20 lakhs incase of Supplier of Services/Mixed Supplies.

not only aggregate turnover
if u are doing any inter state supply of goods it is complusory but not service ... for service check turover limit
if u are doing any supply through e commerce operatior ,,,,
ny isd, nrtp, tcs, tds ,,,
in above cases u need not to check for turnover
directly have too go 4 registrtion

Refer Section 24 of the CGST Act 2017 i.e. "COMPULSORY REGISTRATION UNDER CERTAIN CASES " for more information.