Notwithstanding anything contained in any other provision of this Act,-

(a) where a requisition is made under clause (a) of sub-section (3) of section 55 or an inspection is conducted under clause (b) of the said sub-section against a dealer, the dealer, subject to such restrictions and conditions and in such manner as may be prescribed, may opt to pay in lieu of tax, interest and penalty payable under this Act, a lump sum amount equal to twice the amount of evasion of tax agreed to by the dealer relating to the block period on the basis of evidence found as a result of requisition or inspection, of books of account or other documents and such other materials or information as is available with the commissioner and relatable to such evidence, at the time of requisition or inspection;

(b) once the dealer has exercised the option under clause (a), he shall not have any right to challenge the evasion of tax agreed to by the dealer in any forum;

(c) the commissioner shall proceed to assess the amount of tax evaded by the dealer during a block period in accordance with the provisions of this Act and the amount in respect of which option to pay lump sum has been exercised under clause (a) shall be excluded from the amount of evasion of tax assessed under this clause;

(d) the total evasion of tax relating to the block period shall be assessed irrespective of the year or years to which such tax relates and irrespective of the fact whether regular assessment for any one or more of the relevant years is pending or not;

(e) the assessment under this section shall be in addition to the regular assessment in respect of each year included in the block period;

(f) the total evasion of tax relating to the block period shall not include the tax assessed in any regular assessment or the tax paid along with the returns filed by the dealer, as tax of such block period;

(g) the tax assessed under this section shall not be included in any regular assessment of any year included in the block period;

(h) where the dealer proves to the satisfaction of the commissioner that any part of the tax referred to under this section relates to a year for which the year has not ended or the date of filing returns has not expired, and the transactions relating to such tax are recorded on or before the date of requisition or inspection, in the books of account or other documents maintained in the normal course relating to such year, the said tax shall not be included in the block period;

(i) the provisions of section 20 shall mutatis mutandis apply to the assessment made under this section.

Explanation.For the purpose of this section the expression "block period" shall mean the period comprising of six years preceding the year in which the requisition was made or the inspection was conducted and shall include the period up to the date of requisition or inspection.