MacBook Stolen and locked remotely through Find My Phone but unable to locate it My MacBook got stolen and I put it in lost mode  in Find My Phone, locked it and got email it successfully locked, but the app couldn't get its location. 

How is this possible?

Is it that the thief has disabled location services on my laptop? But I am wondering how can he disable the them if it's locked with a 6 digit code?
Macbooks don't have GPS chips, so they have to rely on less accurate information - namely, triangulating a position from nearby Wi-Fi's.

While that works great in many cases, there's no guarantee it will. If no Wi-Fi networks are in range, a Macbook may not be able to gauge a position at all.

If the E-Mail pointed out the IP address it was sent from (I've never used this service so I don't know how it works) law enforcement may be able to do something with that - but chances are probably slim, as an IP address can be used by many people at the same time.