The Stable update V11.0.1.0.PEFMIXM has been officially released for Redmi S2/Y2 (codename is ysl). 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 S2/Y2 ROM Topics Xiaomi Devices Index
Download Redmi s2/y2 (ysl) Global MIUI 11 V11.0.1.0.PEFMIXM Recovery ROM with Android 9.0. Firmware size is 1.7 GB.