No! You dont need unlocked bootloader.
use this:
http://4pda.ru/forum/index.php?showtopic=749580&st=560#entry51047067
and this is the right ROM:
https://www.androidfilehost.com/?fid=24694152805484178
Hi mate,
If you want to use unofficial unlock method you will need cracked boot.img every time you flash MIUI ROM or when installing TWRP.
Otherwise you'll get boot loop!
My suggestion is to unlock devise officially.
Regards!