Xiaomi has finally rolled out the Android Oreo Global Beta ROM to the Mi6. The update under scrutiny is in the version 8.1.11 and it is the ROM which carries all the services provided by Google. If you are using your device on the MIUI 9 Global Stable ROM, you will need to shift to another ROM in order to experience this update.
In order to shift to the first Android Oreo Global Beta ROM, you will have to upgrade your MI6 unit to the MIUI 9 Global Beta ROM v7.12.14 based on Android Nougat. Once you have done this, an OTA notification will arrive and update your device to the Android Oreo.
It is advised to take a back up of all your crucial data since your device will lose every information once the Android Oreo Global Beta is installed on it.