How to determine place of supply in case of transportation services

Location of Supplier i.e. GTA is in West Bengal

Place of Supply: as A is registered under GST law, hence location of A i.e. West Bengal (Section 12(8) of IGST Act, 2017)

As Location of supplier and place of supply is within the same state, hence intra-state supply, Hence CGST & SGST has to be paid. 

same, what has to be seen is location of supplier of services and not its registration aspect