SIRI IS ALWAYS ON CAN I DISABLE IT

Maybe you are refrying to VoiceOver or Audio Descriptions (instead of Siri)?

Turn VoiceOver on or off on your Apple TV - Apple Support

Use VoiceOver on Apple TV - Apple Support

Turn Audio Descriptions on or off on your Apple TV - Apple Support

Use audio descriptions on Apple TV - Apple Support

You can turn off Siri in Settings.

Turn Siri on or off on Apple TV - Apple Support

Actually, Siri is on ONLY when you push the button with the microphone icon. On the Apple TV Remote Siri is not listening all the time like on an iPhone or iPad.