iPod Touch 6 battery showing 0%!?

In addition to what Limnos has told you, I notice that there battery indicator is not showing the charging symbol, so the iPod is not currently being charged. Therefore, once the battery drains down, I would expect to see that 0% indicator.

If you have a charger plugged into the iPod, then either the charger device is not switched on or it's not working, or the cable is faulty. One last possibility is that the port that you plug the cable into has dust in it, which is preventing a good electrical connection.

I don't know that there is anything wrong with it. The battery could be fully drained. Have you charged it recently? Even if you have, an iPod Touch is an ancient device and the battery may not be working anymore.