No. ORBI is a "system". Routers and Satellites communicate with each other, and NOT with anything else. You can connect an ORBI router to your existing router in AP (Access Point) mode, and have it connect to a remote Satellite. In that case, most people would turn off the WiFi function on their existing router and enjoy the benefits of seamless transition between the ORBI router and satellite using a single WiFi.
There are other ways to extend an existing WiFi sytem, but not the way you are proposeing.
What is the size of your home? Sq Ft? 30 feet is recommended in between base router and satellite to begin with depending upon building materials.
5000sq ft I use one base router and one satellite 40 feet in between.
The Orbi wifi is designed to be the only wifi source with in the home. Having other wifi can and will cause interference problems. You can turn OFF other wifi on routers and use the Orbi in AP mode if you wish to use a different router as your main host router.
