The European Moto G 2015 XT1072 model is finally receiving the Android 6.0 Marshmallow update with software version 24.41.34.en.EU.
The OTA update is 500MB in size and is already on the roll as we speak. If you haven’t received the update yet, go to Settings » About phone » Software updates and hit the Check button to manually check for the update.
If you’re rooted or have a custom recovery installed, you might not be able to install the Marshmallow OTA to your device. In that case, either get unroot and get the stock recovery back on your device or wait until someone cooks up a TWRP recovery flashable pre-rooted stock Marshmallow ROM with software version 24.41.34.