Hi,

If you are administering this UNIX sytem remotely, and you issued an init 0 command, then (unless something went wrong to stop the process) the system will be shut down. It won't be rebooting or coming back up on its own. A reboot would have been init 6 instead.

So to get this server back up, someone will have to physically power it back on or reset it. If you have some kind of console/KVM you can connect to remotely to power it back up then you might be able to get away with an on-site visit. Otherwise, this needs someone to go to and stand in front of the server and boot it back up.