Here, I provide a method to root the Galaxy S III SCL21 (Progre). After downloading the
SCL21 CWMrecovery.rar(download link,
http://pan.baidu.com/s/1h62w1), unrar the file and use the
Odin3 v3.07.exe to flash the
SC06D-JB-KBC-CWM-V6.0.1.2_r10-recovery-odin.tar.md5 recovery. Then boot into the recovery mode to flash the
SCL21_ROO.zip to root the phone. The screen in the recovery mode is reversed. Don't worry about that. just flash the zip file. After flashing, boot into the normal mode and you will find that your phone is rooted. This has been tested in my own unlocked Progre.