Need help solving /efs problem

[Shedopen123]

I have a Samsung galaxy tab 2.One day as I decided to wipe everything,i noticed a message in the recovery mode saying unable to mount efs.I cant open my tablet or anything.After looking on the internet,people were telling me to flash a custom recovery like CWM.In order to do that I need to root my tablet.To root my tablet I need to enable USB debugging,which I can't because I can't access it.Can you help me please?

 

[Jfalls63]

Can you get into download mode?
To flash either the stock firmware or a custom recovery with Odin, USB debugging does not have to be enabled.
What is your complete model number?

 

[Shedopen123]

Can you get into download mode?
To flash either the stock firmware or a custom recovery with Odin, USB debugging does not have to be enabled.
What is your complete model number?

The model number appears to be GT-P3113.Is flashing a stock firmware all I have to do?I already flashed TWRP.Having some trouble rooting it with SuperSu,as whenever I type SU in the terminal,it always says SU not found.Thank you.

 

[Jfalls63]

This should be the stock firmware.
https://www.sammobile.com/firmwares/galaxy-tab-70/GT-P3113/

Does your model have a SD card? If so, copy the SuperSU update zip file to it or internal storage then flash/ install with TWRP.

If flashing the stock firmware doesn't fix the EFS issue, motherboard might be borked.

 

[Jfalls63]

Problems with EFS usually results from corrupt modem/Baseband and if no problems with motherboard, flashing stock firmware should fix it.