Admin commission setting

Hello Wclovers,

I want to ask that how I can add tax on commission earn by admin and also charge 2nd tax called TCS on total sales of vendor.
According to Indian Taxation rule or GST act Ecommerce operator have to charge GST tax @ 18% on the commission earned from vendor and also have to collect TCS tax @ 1 % from vendors total monthly earnings.
The issue is the goods sold by vendor are taxable and the commission setting are charging commission on the value including tax.
ex:-
value of good = 500 Rs
GST tax charge= 50 Rs
total value = 550 Rs

The commission is charged on 550 Rs and I want to charge commission on 500 Rs i.e excluding tax.
Also TCS tax is charge on the vendor earnings excluding tax:
value of goods= 500 Rs
GST tax charge= 50 Rs
TCS charge = 5 Rs (TCS is charge on 500 Rs)

I want to know that how I can charge TCS tax on total earning of the vendor and also how to collect admin fee based on value of goods excluding TAX:
WITH SIMPLE EXAMPLE:

Vendor side:

Value of goods = 500 Rs
GST charged by vendor to customer = 50 Rs
Total amount to be paid by customer = 550 Rs
(Admin side):
Total vendor earnings excluding admin fee and tax (Gross) = 550 Rs
Admin fee @ 10% on value of goods, 10% of 500 Rs = 50 Rs (substract)
GST on Admin fee to vendor @ 18% (GST charged on 50 Rs) = 9 Rs (substract)
TCS charged on Vendor total earning(i.e 500 Rs) @ 1 % = 5 Rs (substract)
Final Vendor earning after admin fee and tax(NET) = 436 Rs

Above was the example how the TCS and GST taxes are charged.

How I can charge GST on commission earned excluding tax and how I can charge TCS excluding tax.

I hope you got it what I meant to say.

A small help is really appreciated.

Thank You.