all my televisions are equipt for viewing Rocu, do I still need to have a box on each television or just one router to control all of them

Ed, You don't need a Comcast box per TV but it depends on your meaning. When you say your televisions are equipped for Roku, do you mean they're smart TV's, and have a Roku app then you only need a central modem and/or router. If you do not have a smart TV, then yes, you'll need to have a separate Roku device per TV. That being said in either scenario you only need a single modem/router.

Honestly that has nothing to do with your Roku