Depreciatiom

Rule 5 of income tax act has been amended to restrict the rate of depreciation to 40%. Therefore, those assets which had been enjoying rates like 50%,60%,80% and 100% will now be restricted to 40% .This is applicable to companies who have exercised option u/s 115BA(4) to pay tax @ 25% instead of 30% with effect from 1st April 2016. For other companies,it shall be effective from 1st April 2017. Therefore from 1st April 2017 (i.e, AY 18-19), for all companies depreciation shall be restriccted only to 40%

Refer - https://www.in.kpmg.com/taxflaashnews/CBDT-Notification-Rules-amended-to-restrict-depreciation-rate-at-40-per-cent-1.pdf

Read the bare section also to get a full understanding of the case.