The preference for either v4 or v6 is embedded in the applications.
Just do a google search on: ipv4 ipv6 preference.
If your network uses dns, you could somewhat steer this by only providing a response for one protocol or the other.
The best option would be to configure the application appropriately, if possible.
If you have no options to configure this, you can test the default behavior by using a packet tracer or ultimately configure the machine on which such an application runs to use only one protocol.
regards,
Leo
