Verification failed on ipod 6th generation
I Would start with restoring the iPod using Device Firmware Update (DFU). You can put your iPod in DFU-mode using these steps (source):


Connect your iPod to iTunes
Hold the power button (the one on the top) and the home button (the one under the screen) for approx. 10 seconds
The iPod will be turned off, release the power button but keep holding the home button for another 13-15 seconds.
iTunes will say it has found an device that needs to be restored.


You can now follow the steps in iTunes to restore the iPod. After the iPod is restored, configure it again and see the problem is solved.

If the problem is not solved, it's likely an hardware issue. You can visit a local apple store to send it in for repairs. It's probably good to make an appointment with Apple Care. Apple Care numbers for your country can be found on this page