My Siri Remote is not working for games downloaded on apple tv.

The Siri Remote (2nd generation) unfortunately doesn’t have the gyroscope and accelerometer that the Siri Remote (1st generation) had. Please use a compatible game controller for these kinds of games.

Connect a wireless game controller to your Apple device - Apple Support

Use Bluetooth accessories with your Apple TV - Apple Support

Identify your Apple TV remote - Apple Support

Also see:

Question 252743313, 252822384, 252842094, 252889701, 252952561, 252984046*, 252996379, 253026378, 253098608.