Time Of Supply for Service Availed from a GTA

1) Pay in August return, as :

Time of supply in case of supplying services when taxes payable under reverse charge mechanism, whichever is earliest from the following dates:-

the date of payment; or

the date immediately following after sixty days from the date of issue of the invoice by the supplier; whichever is earlier

However, if it is not possible to find out the time of supply in aforementioned cases, the time of supply will be considered the date of entry in the books of account of the recipient of the supply.

Since you made the payment on 2nd August, time of supply will be 2nd August.

2) Place of supply in case of transportation of goods is:
location of recipient if recipient is registered. So it doesn't matter from where and to where goods are transported. So compute accordingly.

thanks a lot. so since I'm recipient I need to pay cgst and sgst.

If your location and supplier's (GTA service provider is in same state) then yes, cgst & sgst.