HDFC Securities will auto square off intraday positions a little before closing time if you yourself do not square off your positions. Instead, you can set your own time to auto square off your positions.

After logging in, tap on More at the top left corner of the screen. Under Accounts, Tap on Preference. Widow will open as shown below containing option as 'Auto Square-off Time' set as 'Not Enabled Yet' as default, if Auto-Square-off is not set

Set the time in the drop up window.