Help getting started with Roku devices, including setup, connecting your device to your TV, linking a Roku device to your account at my.roku.com/link, adding channels, subscribing to services, and more.
I''m afraid you need to provide a lot more information. Hook them up in what way? If they're not Smart TVs, then there's no network connection. Are you trying to use one Roku device to connect to multiple TVs? That can be done with an HDMI distribution amplifier. A simple splitter might be OK for feeding just two TVs, although if it's 4K you still might have issues.
What exactly are you wanting to do?
Dan Roku Stick (3600), Ultra (4640), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.