GST on commission received from Overseas (Outside India)

Dear Sir, I am dealing in Petroleum Products in International Markets. I am quite concerned about a few points and if you could assist me with. 1) The Buyer of Petroleum Product is in Taiwan & the Supplier is in Russia. But the supplier is using his Fiduciary Bank Account for receiving the payments in USD. 2) I am purely an intermediary who is entitled to receive the "commission". 3) My commission is roughly $15,000++ USD/Month (Forty Thousand) which will be wire transferred to my account by the Supplier officially with proper documentation. 4) Main Question - Currently I am holding an INDIVIDUAL CURRENT ACCOUNT for receiving the commission. After the completion of the 1st two transactions, I will open my company and receive the commission in the company account. However, at this moment, how much GST is applicable to me and can I register for GST after I have received the commission or do I need to register before receiving the commission? Seeking your assistance, Truly, Raj