Section 273A (4) empowers the Chief Commissioner or the Commissioner that he may, on an application made by the assessee in this behalf, and of course after recording his reasons br so doing, reduce or waive the amount of any penalty payable by the assessee under this Act or stay or compound any proceedings for the recovery of any such amount, if he is satisfied that
(i) to do otherwise would cause genuine hardship to the assessee, having regard to the circumstances of his case.
(ii) the assessee has co-operated in any inquiry relating to the assessment or any proceeding for recovery of any amount due from him.
Section 273 A (5) says that every order made under this section shall be final and shall not be called into question by any court or any other authority.
Regarding waiving or reducing the penalty u/s 273A, the Board of Direct Taxes in one of its circulars has stated the opinion of the Ministry of Law that the discretion to reduce or waive penalty can be exercised only in those cases where the return of the income was duly filed before the last day of the relevant assessment year.