Default [Q] 3G not working

How to fix 3g? I am using Z919 ROM 4.1.2.... I like that ROM but 3g doesn't works. Which files I have to replace using stock ROM? Can anyone help please.
Device: Samsung Galxy SIII GT-I9300
ROM: Temasek's Unofficial CyanogenMod 11
Android Version: KitKat 4.4.4
Kernel: Boeffla Kernel 2.4 Beta 3 NG

Device History:
Ericson T28S -> Nokia 1100 -> Nktel phone (Forgot Model) -> Qmobile Noir A6 A.K.A Micromax A68 -> Qmobile Noir A10 A.K.A Micromax Canvas 2