Gst on directors sitting fee

Plz clarify regarding following:

1.  Company situated in state A holds Board meeting in state B. Which tax is to be paid by the company under RCM for sitting fee:

A.  If both company and director reside in state A.

B.  If director is situated in a state other than     State A.

If SGST IS PAYABLE, PLEASE TELL SGST OF WHICH STATE IS PAYABLE