Yes, it should. For confirmation, visit a LTE zone and try connecting to data connection, if your phone shows 4G or LTE signal then you're good to go, in that case you might as well perform a speedtest.
Edit: In case you currently don't have a Zong 4G SIM, you can simply go to a LTE zone and manually search for available networks. If it shows Zong 4G as one of the options then that also confirms it.
In order to use 4G, you'll need a 4G-capable SIM as well, you can get one from Zong's franchise.