In order to get the credit of the margin amount immediately in your linked savings account,  you have to release the funds from the trading account after Squaring off the position. The path is as follows: Limits-> Hold/Release-> Amount to be released-> Release

However, if you do not release the funds from your end, the funds will be released after completion of end of day processing of AxisDirect and you will not be able to withdraw the funds in the interim.