I got root on my blu studio touch.
The steps are:
1) unlocked the bootloader,
2) Flash TWRP on fastboot mode,
3) Boot into TWRP ("adb reboot recovery"). If you encounter bootloop, turn off the phone and manually boot into TWRP.
4) In TWRP you have to format the phone (this will erase everything but when you unlock the bootloader it erases everything anyway).
5) Reboot to recovery in TWRP after formatting the phone.
6) Connect the blu studio touch to the computer and move the supersu to internal memory and flash supersu.
7) Reboot the phone and you should have supersu on the phone.
Note: This procedure doesn't require splash tool. The TWRP on this thread works.
Any roms for this phone? like LOS