Hello there.
Volume+, volume- and power doesn't work on my Redmi Pro. But TWRP still can be run by command:
$ fastboot boot TWRP-3.0.2-0-omega.img
. And it starts after about half minute after the command. I've tried to flash TWRP with adb shell:
# dd if=TWRP-3.0.2-0-omega.img...