(1) If the Commissioner is satisfied that a return furnished under section 7 in respect of any period is correct and complete, he shall, by an order in writing, assess the tax payable by the dealer on the basis of such return.
(2) If the Commissioner is not so satisfied he shall serve on the dealer a notice requiring him on the date, and at the hour and place specified therein, either to attend in person or to produce or cause to be produced any evidence on which he may rely in support of his return.
(3) On the day specified in the notice under sub-section (2) or as soon thereafter as may be, the Commissioner, after hearing such evidence as he may require, shall, by an order in writing, assess the tax payable by the dealer.
(4) If a dealer fails to make a return as required by section 7 or having made the return fails to comply with any of the terms of the notice under sub-section (2), the Commissioner shall, by order in writing assess to the best of his judgment the tax payable by the dealer:
Provided that before making assessment the Commissioner may allow the dealer such further time as he thinks fit to make the return or comply with the terms of the notice issued under sub-section (2).