Xiaomi has been testing Android 11 on the Mi 10 Pro for a while now. The first build based on Google's latest OS arrived in September, but neither V12.1.2.0.RJACNXM or V12.1.3.0.RJACNXM made it out of Stable Beta testing. Xiaomi then released V12.2.1.0.RJAMIXM for the global model, although again as a Stable Beta update.
This build has now passed Stable Beta testing though and should now be rolling out to all global handsets. As far as we can tell, Xiaomi has only rolled out Android 11 to devices in its home country of China, making V12.2.1.0.RJAMIXM the first of its kind. It seems that other devices will not be waiting long before they receive Android 11 outside of China, too. Xiaomi has just issued a new Stable Beta update based on Android 11 for the Mi 10, for example, albeit on the European branch of MIUI.
Additionally, V12.2.1.0.RJAMIXM contains a few changes beyond Android 11. According to the screenshot below, the update upgrades the Mi 10 Pro to the October 2020 security patch. Moreover, Xiaomi has improved AI moonscape functionality and has updated the vlog feature set on MIUI 12. V12.2.1.0 brings new vlog templates, along with the ability to save them as drafts. If upgrading via the OTA is not your thing, then you can download the recovery and fastboot files to upgrade the Mi 10 Pro to V12.2.1.0.RJAMIXM via the Mi Community.