Capital gain tax on house

An amount kept in capital gain account for 6 months or more, say this is kept in Capital Gain Fixed account.

The holder of such account can withdraw or use the Interest amount accumulated every three months? the use is other then the buying property in othere works to cover the expanses toward the checking of the authenticiy of new property documents.

Or

He can only get the benefits of this interest at the time of paying to purchase property along with the principal amount or Capital gain funds.

Thanks!