I have already specified in the manifest as Landscape and LandscapeFlipped, I know this is just a preference and on top of this I've added the below code in the App.xaml.cs OnLaunched. But yet when tested on a tablet the app goes back to portrait mode.
DisplayOrientations.Landscape | DisplayOrientations.LandscapeFlipped;
Since my comment helped you im going to add it as answer
[DllImport("user32.dll", EntryPoint = "#2507")] extern static bool SetAutoRotation(bool bEnable); SetAutoRotation(false);