Companies act 2013--depreciation

As per SCHEDULE II (See section 123) USEFUL LIVES TO COMPUTE DEPRECIATION part C of Companies Act 2013, note no. 7

From the date this Schedule comes into effect, the carrying amount of the asset as on that date—
(a) shall be depreciated over the remaining useful life of the asset as per this Schedule;
(b) after retaining the residual value, shall be recognised in the opening balance of retained earnings where the remaining useful life of an asset is nil.

Hope this is clear to you.