GTA exemption

If what you hired is a local transport vehicle,  there is no GST and it will not fall under GTA. GTA is a party which issues a Consignment note.

If you actually hired a GTA and still the hiring charges for the entire vehicle are Rs. 1200/- (below 1500/-), then no GST, but this scenario is very unlikely.

If what you are hiring is their service to send your a small consignment outstation in their (big) vehicle and the charges are above 750/-, and if you are the one making payment for the service (not the consignee), then you would need to pay 5% on RCM. If consignee is making the payment, consignee has to pay  GST on RCM basis (assuming consignee is registered).