Calculation of gross receipt (inclusive or exclusive of gst)

Request guidance on the following query:

Receipt of Commission by a distributor on distribution of financial instruments normally includes GST of 18% (under forward charge mechanism).  The distributor is liable to segragate the gst part from commission earned in order to remit to the government.

Is it necessary to take full amount of commission including GST in order to determine the amount of gross receipt for the purpose of Tax Audit?