Is my commission from out side india is taxable under GST ?

Hi, I am an India individual, I have a partnership farm . Me and my wife is a partner on this farm. Currently we start selling petroleum oil product of some refinery of United States and gulf. We are getting commissions from those refinery to sell its product. The commissions will be more a million dollar due to bulk quantities of the products. Ans it's will be 8 crore approx in india currency. We do the NCNDA/IMFPA agreement with the refinery for commission. If I get the commission of this amount in my firm current account. And also get marked up from the seller, Question is, Q1 what type of document bank will be ask for clear the fund. Q2. Is this transaction will be come in GST ? Q3 Is this type of commissions is legal in India, because there no good comes in India and no goods go from India. So it's legal. Q4. What type of document we need to proof of.this fund. Q 5. Is Government authorities asking me the proof of the transaction. Q6 is marked up is allowed in india from out side of India?