To my understanding, Interest u/s 234B & C was not excluded before the amendment vide Finance Act, 2016. I am clarifying the position as follows:
The advance tax was payable in respect of an eligible business referred to in section 44AD-
Pre-amendment
Due date of instalment | Amount payable |
On or before the 15th September | Not less than thirty per cent of such advance tax. |
On or before the 15th December | Not less than sixty per cent of such advance tax, as reduced by the amount, if any, paid in the earlier instalment. |
On or before the 15th March | The whole amount of such advance tax as reduced by the amount or amounts, if any, paid in the earlier instalment or instalments : |
Post Amendment
to the extent of the whole amount of such advance tax during each financial year on or before the 15th March
Thus, Finance Act, 2016 has provided a benefit to eligible assessee in respect of eligible business declaring profit from business under section 44AD by way of one time advance tax payment before 15th March.
It does not mean that there was no advance tax before the amendment.