If you have TWRP installed, I assume you were running a custom rom?
1.) If you had made a backup via TWRP prior to wiping everything, you should be able to restore that backup.
2.) If no backup, you could re-install your rom. Do you still have a copy of it?
3.) If not, you could download a rom for your device and try installing it.
4.) I'd use the ruu as a last resort but you have to have the correct one for your specific model and the correct Android version. Also, I'm going to assume you have an unlocked bootloader since you installed TWRP. If so, the bootloader has to be relocked prior to running an RUU