You can now download the MIUI 11 for the Xiaomi Mi 6 and Xiaomi Mi Mix 2. The Xiaomi Mi 6 has version number V220.127.116.11.PCACNXM and Mix 2 has version number V18.104.22.168.PDECNXM.
After downloading the update:
- Go to Settings > About Phone > System updates
- Press 10 times MIUI logo
- Click on three-dot at top right
- Select Choose update package
- Now select the downloaded file in storage
Note: These ROM from China channel.