In my opinion, the assessing officer is correct in applying the rate mentioned under section 115 BBE for the unexplained investment.
One of my clients, a partnership firm, declares excess stock at the time of 133A survey. Now the assessing authority treats the excess stock declaration as investment u/s 69B as an unexplained investment and adopts tax rate as per section 115BBE. The A.Y. is 2018-19. The declared amount is recorded in books of accounts of A.Y.2018-19 as declaration u/s 133A and tax is paid at the normal rate in the case of the Firm.
In my opinion, the assessing officer is correct in applying the rate mentioned under section 115 BBE for the unexplained investment.