The Stable update V13.0.1.0.SCVCNXM has been officially released for Redmi 12C / POCO C55 (codename is earth). 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 MIUI or HyperOS 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: Redmi 12C / POCO C55 ROM Topics Xiaomi Devices Index
Download Redmi 12c (earth) China MIUI 13 V13.0.1.0.SCVCNXM Fastboot ROM with Android 12.0. Firmware size is 332 Bytes.