1. As per Notification 5/2017 CT : GTA is not liable to obtain Registration only in case if Recepeint of his services discharge tax liability under Reverse Charge.
2. As per Notification 12/2017 CT (R)
Since GTA providing services in the course or furtherance of business for consideration, therefore these services are considered as Supply as per Section 7 of CGST Act, 2017, Moreover as per Notification No. 12/2017- Central Tax (Rate), – Exempted Supplies Entry No 18, Heading 9965 Services by way of transportation of goods- (a) by road except the services of— (i) a Goods Transportation Agency; (ii) a courier agency; Therefore GTA services are Taxable Supplies.
3. As per Notification 32/2017 CT (r) GTA Services other than the following recipients is TAXABLE
(a) any factory registered under or governed by the
Factories Act, 1948(63 of 1948); or
(b) any Society registered under the Societies Registration
Act, 1860
(c) any Co-operative Society established by or under any
law for the time being in force; or
(d) any body corporate established, by or under any law
for the time being in force; or
(e) any partnership firm whether registered or not under
any law including association of persons;
(f) any casual taxable person registered under the
GST
So if GTA is providing services to other than those specified category recipients as discussed above such as to an Individual / Proprietorship Firm/HUF. In such scenario GST shall be paid by GTA itself on forward charge mechanism @ 5% (Where Receptient is not doing RCM)
So GTA is Registered, means need to obtain Registration if he discharge tax liability in FC @ 5% or @ 12%.