Xiaomi has started rolling out the stable build of Android 7.0 Nougat to Mi Max. The update is being rolled out over the air as we speak.
The Nougat update hitting Xiaomi Mi Max is based on the global MIUI 220.127.116.11 stable ROM. It also bundles May security patch. Currently only the 3GB version of Mi Max have reported receiving the Nougat update. And it is not clear as to when the Xiaomi Mi Max Prime with 4GB RAM will get the befit of Nougat goodies.
As is the case with OTA updates, it may take a while to reach your Mi Max device. In case you are too impatient to wait, you can check for it manually by heading to Settings > About device > System update. However, do keep in mind that you will be required to charge your handset sufficiently and connect it to a WiFi network before hitting the download button.
Notably, the Android 7.0 Nougat update for Xiaomi Mi Max as an official developer preview ROM was rolled out in February.