Section 9(1) reads: "The tax payable by any dealer under this Act on sales of goods effected by him in the course of interstate trade or commerce, whether such sales fall within clause (a) or clause (b) of section 3, shall be levied by the Government of India and the tax so levied shall be collected by that gov ernment in accordance with the provisions of sub section (2) in the State from which the movement of goods commence: Provided that, in the case of a sale of goods during their movement from one State to another, being a sale subse quent to the first sale in respect of the same goods, the tax 34 shall, where such sale does not fall within sub section (2) of section 6, be levied and collected in the State from which the registered dealer effecting the subsequent sale obtained or, as the case may be, could have obtained, the form pre scribed for the purposes of clause (a) of sub sec tion (4) of section 8 in connection with the pur chase of such goods." Sub section