how to root+twrp redmi note 3 [mtk] china stable 7.5.1.0?

my device has updated to china stable 7.5.1.0 but that back to unroot and lost my twrp recovery..
i'm trying to root via latest kingroot version its always notified "no root strategy"..
then i'm install twrp via adb, i can't adb reboot bootloader (fyi my device has officialy unlock bootloader before) :crying:

how to root that china stable 7.5 on my redmi note 3 mtk?