Android max limit for geofences?

You get 100 geofences per app per device

You can have multiple active geofences, with a limit of 100 per device user. For each geofence, you can ask Location Services to send you entrance and exit events, or you can specify a duration within the geofence area to wait, or dwell, before triggering an event. You can limit the duration of any geofence by specifying an expiration duration in milliseconds. After the geofence expires, Location Services automatically removes it.

https://developer.android.com/training/location/geofencing.html

they tell you in the google IO session called Beyond the Blue Dot: New Features in Android Location