One year multiple visit visa must go out side KSA after 3 or 6 Month?

Hello Dear Friends

I have question. I am going to bring my family here in KSA on one year multiple visit visa.
But before I apply I want to make sure that my family has to go out side kingdom after 3 months or 6 months? When they must to out side kingdom. If you have confirm information please do advise me.
Thanks

Intial visa is valid for 90 days but it can be extended for 90 days more using abshir before the expiry of 90 days intial stay.