place of supply

CA Arun Gupta (CA) (173 Points)

11 June 2017  
I m ca reg in lucknow. I got bank audit of bank branch situated in lucknow only. however I got appointment letter from bombay head office nd I also billed my services to bombay head office nd got payment from head office. Then what would be the place of supply.? plz answer with the specific section or explanation or source of information