I want to hook up my Apple tv 4th gen to multiple tv sets, can this be done and how?

If you mean to display simultaneously, no.

You would need to get an HDMI splitter. Though the downside is both TVs display the same media. I.e. You can't watch Netflix on one and iTunes on another...

here's a thread about the same topic Apple TV 4...Does Apple TV 4 work on multiple TV sets?

All you need is an HDMI splitter and HDMI cable. I did it and it works great.

Do a search on Amazon for the splitter. I had great luck with the J-Tech brand.

Apple TV 4...Does Apple TV 4 work on multiple TV sets?