You mentioned in your first post this:
...i have developed the app in unity 4.6 on windows pc.. transferred the files to mac...
so, I thought you were building the project on Windows and then copying the generated Xcode project to Mac.
But if you are now building the Unity project from Mac, then I guess the problem is that you are using Vuforia 3.0 on Unity 5;
Compatibility with Unity 5 has been introduced with Vuforia 4.0.105 and later versions (current version is Vuforia 4.2.3);
so, either you use Unity 4.6 OR you upgrade to Vuforia 4.2.3.
Also, note that Vuforia 3.0 does not support 64bit builds on iOS, which is now mandatory for submitting Apps to Apple.
Vuforia 4.0 and 4.2.3 support iOS on both 32bit and 64bit modes.
So, either way, if you are targeting the iOS platform, the recommendation would be to upgrade to Vuforia 4.2.3