Redmi has released the MIUI Update 12.5.2 for Redmi Note 9 Pro Max which also brings the September 2021 Security Patch. Has brought noticeable smoothness to the UI and system and performance.
Xiaomi Redmi Note 9 Pro Max was released on 12th of May 2020 with Android 10 with MIUI 12.
Redmi Note 9 Pro Max received the major Android update to Android 11 with only a single MIUI update so far and hence we can expect its MIUI 13 and 14 respectively.

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The Xiaomi Redmi Note 9 Pro Max came with an Android 10 out-of-the-box and got upgraded to Android 11. Therefore, it is eligible for the upcoming Android 12 update.
Hence, the Android 12 will most probably be the last major OS update on this device.
The Redmi Note 9 Pro MIUI 12.5.2 stable update has begun rolling out and it will reach users soon.
Once the update is available on your device, you can head over to Settings >> About Phone >> Software Update section to update your Xiaomi device with the latest update.
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