can i connect 4 homepod minis to one apple tv? im trying to get 4 speakers to stream in the 4 corners of a home gym

You can’t pair 4 in one set, so two pairs.

Set up HomePod stereo pairing - Apple Support

It will play on all in sync

You can stereo pair two minis if you like, then on Apple TV you can AirPlay:

1. On Apple TV, press and hold Apple TV App/Home  to bring up Control Center. 
2. Select AirPlay .
3. Choose the HomePods