The Redmi Note 10S is one of the first device's receive MIUI 12.5 globally. The update is available for devices enrolled on MIUI's European and Global branches, and will be distributed as an OTA download. The Redmi Note 10S should arrive with MIUI 12.5 in India when it launches later this week, too.
https://www.notebookcheck.net/Xiaomi-Redmi-Note-10S-receives-MIUI-12-5-globally-just-days-ahead-of-Indian-launch.538931.0.html