The Stable update V11.0.4.0.QJXINXM has been officially released for Redmi Note 9 Pro Max (codename is excalibur). 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 Note 9 Pro Max ROM Topics Xiaomi Devices Index
Download Redmi note 9 pro max (excalibur) India (IN) MIUI 11 V11.0.4.0.QJXINXM Recovery ROM with Android 10.0. Firmware size is 2.6 GB.