While using the remote computer via mstsc, suddenly it hanged. I am unable to do any operation. Even unable to restart the computer from command window (shutdown -r). Could you please provide the way to restart the remote computer without human intervention.
Your question is unclear but I'm going to assume you can't reach the machine via RDP.
The answer is, not much unless you're prepared with back up solutions incase of this issue.
Unless you have any super LAN card which provides access to the same machine via another IP so you can possibly load up another OS (assuming it's dual boot) or that the LAN card has the ability to force a restart, you probably can't (AKA DRAC)!
Or, you may get really lucky (depending on the nature of the hang) if you have remote software like LogMeIn or TeamViewer etc which may still be able to do this.
Last option, if you can log onto another machine on the same network as the faulty machine you could possibly issue a remote shutdown command, but this depends on the permissions etc. Or maybe if you can RDP to another machine, that machine could take over the computer over it's LAN? Something like
Lastly, wait a while, see if the machine either comes out of the crash.