68[Penalty not to be imposed in certain cases.
273B. Notwithstanding
anything contained in the provisions of 69[clause (b) of sub-section (1) of] 70[section
271, section 271A, 71[section
271AA,] section 271B 72[, section 271BA], 73[section
271BB,] section 271C, 74[section
271CA,] section 271D, section 271E, 75[section
271F, 76[section 271FA,] 77[section
271FB,] 78[section 271G,]] clause (c) or clause (d)
of sub-section (1) or sub-section (2) of section 272A,
sub-section (1) of section 272AA] or 79[section
272B or] 80[sub-section (1) 81[or sub-section (1A)] of section 272BB or] 82[sub-section (1) of section 272BBB or] clause (b) of sub-section (1) or clause (b) or clause (c) of sub-section (2) of section
273, no penalty shall be imposable on the person or the assessee, as the
case may be, for any failure referred to in the said provisions if he proves
that there was reasonable cause 83 for the said
failure.]