If Tax Payable amout is above Rs.1 lac then 234A attracts, since the original date for ITR of tax audit was 31st October the interest will be calculated for 3 months (Nov- January)
As per Extension notification, It is clarified that the extension of the dates shall not apply to Explanation 1 to section 234A of the Act, in cases where the amount of tax on the total income as reduced by the amount as specified in clauses (i) to (vi) of sub-section (1) of that section exceeds one lakh rupees.
So, if your SA tax liability is more than 1 lakh, than Sec. 234A triggered from original filing date