The Stable update V9.6.6.0.OCBRUFD has been officially released for Redmi 6A (codename is cactus). 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 6A ROM Topics Xiaomi Devices Index
Download Redmi 6a (cactus) Russia (RU) MIUI 9 V9.6.6.0.OCBRUFD Fastboot ROM with Android 8.1. Firmware size is 2.1 GB.