iBrootal:
Your question isn't detailed enough.
Take note that Siri on the AppleTV remote, and Siri on the iPhone or Apple Watch each have different capabilities even in the same HomeKit home. Here are some examples, where Apple TV is my HomeKit hub:
Works:
1. On my iPhone or Apple Watch: "Hey Siri, Play 'Band of Horses essentials in the Living Room'". Plays Apple Music playlist in the next room on the surround sound system connected to Apple TV.
2. On my Apple TV remote: "Hey Siri, Play 'Band of Horses essentials". Do
3. On my iPhone or Apple Watch: "Hey Siri, unlock my door"
Not Allowed:
1. On my Apple TV remote: "Hey Siri, Play 'Band of Horses essentials on my iPhone". iPhone is not a HomeKit destination, maybe?
2. On my Apple TV remote: "Hey Siri, unlock my door". Likely not allowed because there isn't enough security?