Question: I have a multitab application where I want the display orientation the same for one tab and dynamic for the other, that means I need for example for 

Tab1 = always portrait orientation
Tab2 = automatic detection plus orientation

I have tried to disable the orientation on Tab1 but that will disable the orientation in the whole app.

Any help?!

Answer: 
From Apple docs:

"Tab bar controllers support a portrait orientation by default and do not rotate to a landscape orientation unless all of the root view controllers support such an orientation. When a device orientation change occurs, the tab bar controller queries its array of view controllers. If any one of them does not support the orientation, the tab bar controller does not change its orientation."

So the answer is no you cannot do what you are trying to do, it's an all or nothing kind of situation.
If you have not already used, I think calling different UIView for different Tab will help you to do so.  

If you have used it, then making 2 different ViewControllers and handling the same thing different may help you to do so.