Various new Android 11-based custom ROMs have been appearing for a number of Redmi devices, with the especially popular Redmi Note 8 and Redmi Note 8T getting the unofficial Android 11 treatment. The custom ROM for the Redmi Note 9S is in an alpha stage so may not appeal to all users and the aging Redmi Note 5 Pro is covered by LineageOS.
https://www.notebookcheck.net/Redmi-Note-8-Redmi-Note-8T-Redmi-Note-9S-and-even-the-Redmi-Note-5-Pro-get-special-Android-11-based-custom-ROM-treatment.494836.0.html