To get this Google Assistant feature the Android TV-based devices should run on at-least Android Marshmallow (6.0). Google has already revealed some devices that will be getting Google Assistant feature this year. The devices are AirTV Player, All Android TV’s in the US running on Android 6.0 or Android 7.0 (including Sharp Aquos & Sony Bravia lineup), Nvidia Shield and Xiaomi Mi Box. Although NVIDIA Shield will be the first TV device to support Google Assistant and rest devices will get it later.
You will need to activate Google Assistant by using a button on the remote control or say “OK Google”. In some cases you will most probably need a voice remote to use it. Nvidia Shield will be device to offer a hands-free Assistant experience that means you just need to say “OK Google” to activate it. Google is also working to bring its Assistant feature to few more devices this year, like Android Wear 2.0 based smartwatches and Android powered in-car systems. Google is also going to collaborate with Mercedes and Hyundai to bring third-party services to Google Home.
