The feature also supported up to four users at once, but now it looks like Instagram has quietly updated the feature where it will now support up to six users at once. This is according to Instagram’s Help page where it states that users will be able to video chat with up to six people at the same time. Launching the video chat feature will be the same as before, so there is no change in that, just that it will now support more people at once.
We’re not sure if you will need to update the app to enable support for more users, but keeping the app updated is not a bad idea anyway. Like we said, it does seem a bit strange that Instagram is offering group video calls in its app since it isn’t necessarily an app that comes to mind for video chat. In fact WhatsApp (also owned by Facebook) also supports group video calls, so that could be an alternative if you’d rather not use Instagram.