Download a modified unofficial version of TWRP custom recovery with full support for Android Project Treble. With this modded recovery you can easily flash Treble-enabled custom ROM like LineageOS v15.1 on your Redmi Note 4 device. This TWRP allows flashing ROM image file on Vendor partition (sort of).
Despite uncertainty of whether this ever popular Redmi Note 4 will have official support for Project Treble, guys at XDA has managed to build custom ROM making use of the project framework. This custom modded TWRP is surely one of required tools to enable flashing the ROM’s image file.
Check also: Treble-enabled TWRP for Redmi 5A (Riva).
Grab the flash-able image file from the link below. The file is hosted on our US and EU servers supporting resume-able and multiple download connections. The link is provided as mirror link.
Please be aware that the file is meant for Xiaomi Redmi Note 4 codename Mido. Do not attempt to flash it on wrong device or otherwise it might brick your phone.
Mirror on Mega.nz is available here.
Credits: The file was first found by author from XDA. A post shared by Abhishek987. Please let us know if you know the original developers to mention the credits for. Thanks.