An individual who has covered under tax audit shows assets details  in his balance sheet as individual asset like machinery, vehicle, etc..  now he sold one of he car at profit and purchase another after 7 months.My question is whether i should calculate loss/ gain on individual asset or calculate as per block concept. but assets not shown in books as per block. 

If i calculate depreciation as per income tax return( i.e 15% block) it is different from calculation of individual assets concept.

Please help