(1) If the assessing authority is satisfied that the return submitted by an assessee is correct and complete, it may accept the return. If the return appears to it to be incorrect or incomplete it shall, after giving the assessee a reasonable opportunity of proving the correctness or completeness of the return submitted by him and making such enquiry as it deemed necessary, assess to the best of its judgment, the amount of tax due from the assessee.
(2) The amount of tax due from any assessee shall be assessed separately for each year within a period of four years from the expiry of the year to which the assessment relates.
(3) If any assessee has failed to get himself registered or having been registered, has failed to submit any return, the assessing authority shall, after giving the assessee a reasonable opportunity of making representation and after making such inquiry as he deems necessary pass an order assessing the amount of tax due, to the best of its judgment.
(4) The amount of tax so assessed shall be paid within fifteen days of receipt of the notice of demand from the assessing authority.
(5) In making an assessment under sub-section (1), the assessing authority if it is satisfied that the escaped assessment was due to wilful non-disclosure of information or attempt to evade the tax by the assessee, the assessing authority may also direct to pay in addition to the tax assessed, a penalty which shall not be less than one and half times the tax so assessed but which shall not exceed three times the tax so assessed:
Provided that no penalty under this sub-section shall be imposed unless the assessee affected has had a reasonable opportunity of showing cause against the imposition of such penalty.