The Stable update V22.214.171.124.SLTCNXM has been officially released for Xiaomi 12S (codename is mayfly). Before updating, please make sure you have downloaded the exact ROM matching your Xiaomi phone/tablet. In Fastboot mode, you can check model code by typing
fastboot getvar product in cmd/shell.
The firmware files posted here are all official Xiaomi ROM, xiaomiROM.com do not own and never modified those firmwares，you will always download the file from Xiaomi server.
You may interest in those contents: Xiaomi 12S ROM Topics Xiaomi Devices Index
Download Xiaomi 12s (mayfly) China MIUI 13 V126.96.36.199.SLTCNXM Recovery ROM with Android 12.0. Firmware size is 5.5 GB.
Download Xiaomi 12s (mayfly) China MIUI 13 V188.8.131.52.SLTCNXM Fastboot ROM with Android 12.0. Firmware size is 7.9 GB.