The Stable update V8.5.3.0.MALMIED has been officially released for Redmi 3S (codename is land). 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 3S ROM Topics Xiaomi Devices Index
Download Redmi 3s (land) Global MIUI 8 V8.5.3.0.MALMIED Recovery ROM with Android 6.0. Firmware size is 1.7 GB.