Tech company Xiaomi first unveiled its MIUI 12 in China in April, followed by a global launch in May. Presently, reports from Xiaomi suggest that we will be seeing the first set of smartphones to receive the stable beta firmware. This is the final stage of testing before the update gets seeded on retail devices.
The smartphones to get this Beta build include the Xiaomi Mi 9T, Mi 9, Mi 9T Pro and the Redmi K20/K20 Pro. Owners of these devices can gain access to the Stable Beta when they enroll in the Mi Pilot program. You can find details about this here if you own any of the devices listed above and you are interested in helping out with Beta testing.
Presently, these builds are not recommended for installation on your daily driver as certain unexpected bugs may surface, but the build should be stable overall. The new stable build for international users supports multiple languages and Google services.
You can get more information about the MIUI 12 stable betas through this link from XDA Developers.