(1) The proper officer may scrutinise the return and related particulars furnished by the registered taxable person to verify the correctness of the return and inform him of the discrepancies noticed, if any, in such manner, as may be prescribed, and seek his explanation thereto and in case---
(a) the explanation so given is found acceptable, the taxable person shall be informed accordingly and no further action shall be taken in this regard;
(b) no satisfactory explanation is furnished within a period of thirty days of being informed by the proper officer or such further period, as may be permitted by him, or where the taxable person, after accepting the discrepancies, fails to take the corrective measure in his return for the month in which the discrepancy is accepted, the proper officer may initiate appropriate action in accordance with the provisions of this Act.
(2) Where a taxable person fails to furnish the return under section 10, either on his own motion or in response to a notice issued, the proper officer may proceed to assess the liability of cess of the said person to the best of his judgement, taking into account all the relevant material which is available or which he has gathered and issue an assessment order within a period of five years from the end of the month to which the cess not paid relates.
(3) Where a taxable person fails to obtain registration, or whose registration has been cancelled but who was liable to pay cess, the proper officer may proceed to assess the liability of the cess payable by such taxable person to the best of his judgment for the relevant calendar month and issue an assessment order within a period of five years from the end of the month to which the cess not paid relates.
(4) No assessment order shall be passed under sub-section (2) or sub-section (3) by the proper officer without giving the taxable person a reasonable opportunity of being heard.