I wanted to know if the remote to the new Apple TV versions will work to old Apple TV version

The Siri Remote (3rd generation) (latest model) will work with Apple TV boxes on system software version tvOS 15.4 or later.

So if you have an Apple TV HD (4th generation) (A1625) (2015) or later model, then this remote can work.

Earlier models [A1469, A1427, A1378, A1218] do not support the latest model remote.

Identify your Apple TV model - Apple Support

Find your Apple TV model number - Apple Support Apple TV remote models and their compatibility - Apple Support

For compatibility of the Apple TV Siri Remote see the following from: Siri Remote - Apple

• Compatibility
• Apple TV Models
  • Apple TV 4K (3rd generation)
  • Apple TV 4K (2nd generation)
  • Apple TV 4K (1st generation)
  • Apple TV HD

Does the find remote feature work with a 3rd gen Siri Remote on a 1st gen Apple 4K tv?

i can’t seem to get the find remote option to appear. The remote is Siri 3rd gen. And my tvOS is 17.1

Please verify if tvOS 17 also updated the remote firmware.

Settings﹥Remotes and Devices﹥Remote﹥Firmware Version: 0x83.

If not, then allow Apple TV to do so, by keeping the Siri Remote (2nd generation or later) bluetooth connected and charged enough (>50%) for some idle time.

The Find option reveals itself from the drop-down menu at the top device selector in the software remote.

Does the find remote feature work with a 3rd gen Siri Remote on a 1st gen Apple 4K tv?

Yes it does. It depends on the remote model and the tvOS version.