Approve confim users created with other components

You need to run CB > Tools > User Sync to synchronize the two database tables again.

Is there any possibility to trigger this? Or create a sync plugin that syncs tables?
Because when syncing users created via rstickets the confirmed / approved settings are right.

Otherwise we have to contact rsjoomla again or do mannualy sync of users.

The synchronize user function is accessible from backend only. There is nothing to cause a synchronize on frontend. The synchronization can be very heavy and it should only be ran when needed and not on a regular basis as it's going to validate every CB user. You'd have to check the backend code and implement it into RSJoomla, but if you're going to do that you might as well implement CB registration properly.

You're trying to find a hacky workaround for what you're wanting. I don't have one and I wouldn't recommend one. Implement it right if you want it to behave right. That's the only suggestion I can make. For RSJoomla to properly integrate with CB it should use CB API to register a user as detailed in the tutorial provided earlier.

A CB plugin is of no use for this as RSJoomla does not integrate into CB and does not fire CB triggers. You could make a Joomla plugin that hooks into Joomlas user store events, but then when CB stores a user your plugin will fire and you end up with an infinite store loop. The only way for the integration to be proper is for RSJoomla to run CB API. Whether it's done from a Joomla plugin or not is dependent on RSJoomla as they could implement Joomla events and your Joomla plugin would just act on them, which would cover your usecase.