If you want users to log in to your Joomla site using their Invision Community credentials, you can simply do it using our Joomla Invision Community OAuth plugin. Once you configure the Invision Community with Joomla Invision Community OAuth plugin, you can allow users to SSO to your Joomla site using Invision Community.
Similarly, you can map your Joomla roles based on your Invision Community attributes/groups. To know more about other features we provide in Joomla Invision Community OAuth plugin, you can click here.