In my opinion, this is the fastest and most simple way to root the T68.
1) Download
Cydia Impactor. It supports all major desktop operating systems.
2) Connect T68 with a USB cable, but do not enter file transfer mode.
3) Open Cydia Impactor, make sure the default option is highlighted ("drop SuperSU su to /system/xbin/su").
4) Click Start and wait a couple of seconds.
Done.