Re: 802.1X - WPA2-Enterprise Google Authentication and Windows
EAP-TTLS itself is only supported in Windows 10 and above. I have never tried to configure this in group policy myself.
It looks like you need a Server 2012 or newer AD controller to be able to have this functionality. You will of course need your domain running at 2012 level or better, and I'd suggest the forrest should be the same as well.