Quail and Chickens should be kept in separate pens away from each other to keep them from intermingling.
You can however place quail alongside chickens if there is a divider between the two pens in the same chicken coop though.
But the Quail and Chicken should be kept where they can't actually make much contact with each other.
As long as you place a divider between the Quail and Chicken then they can be in the same coop.
There is also a slight issue of disease transmission if the Quail and Chicken are kept together so keep them separate and they'll be okay.