If you are going to do something like that, that means that you are familiar with driver installations and command line.
1. Download Native android from here:
https://pucina.dedyn.io:8181/data/public/8916ec
2. Extract platform-tools.rar from archive downloaded above to somewhere (let's say c:\platform-tools, let's call it N1)
3. Extract folder Native-release to somewhere (let's say c:\Native-release, let's call it N2)
4. Move content of the folder Native-release (N2) (flash_all.bat and folder images) to folder platform-tools (N1)
5. Connect pad to PC
6. In Windows explorer, when platform-tools (N1) folder opened press Shift and right mouse button and select "Open command window here".
6. Boot into fastboot with buttons combination or write in black window "adb reboot bootloader"
7. When you tab in fastboot mode write in black window flash_all.bat
After that, when tab will rebooted you will get native android in it. Now you reboot into fastboot (of course it should be unlocked), flash TWRP. After that install 6.3.17 release from here from TWRP. And now most significant part:
DIRECTLY AFTER FLASH SWIPE DALVIK, CACHE and DATA. DO NOT TOUCH SYSTEM NEITHER BEFORE NOR AFTER FLASH!!!!!
Then flash SuperSU.
I will also create separate thread how to flash SuperSU and TWRP.