Exemption of capital gains requires reinvestment in new assets or deposit to defer tax on shifting industrial undertakings. Exemption of capital gains is available when assets of an industrial undertaking are transferred from an urban area to a non-urban area and the assessee, within the prescribed reinvestment window, purchases new plant or machinery, acquires or constructs premises, shifts and transfers the establishment, or incurs expenses under a notified scheme. If reinvestment cost is less than the gain, the difference is taxable; if equal or greater, no gain is charged. Unused proceeds must be deposited in a specified institution and applied per the notified scheme, otherwise they become taxable when the reinvestment period lapses.