We've encountered some very troubling issues with Unity 4.6.2 and 4.6.3 that we understand their team is continuing to work on. Until we reach a resolution, we recommend using Unity 4.6.1. There's an ongoing thread about the issue here: https://community.leapmotion.com/t/unity-4-6-2-compatibility-issue/2492.
(Before going any further, I should note that the Leap and Oculus plugins will not work together in Unity Free for Mac. More details on why here.)
From there, you should refer to the Leap and Oculus SDK versions that are supported by our Unity assets: https://developer.leapmotion.com/downloads/unity The assets are numbered by Leap SDK release, and have corresponding Oculus SDK supports. As you can see in the tables, the most recent set of assets supports Leap 2.2.2 and Oculus 0.4.4. Be sure to download the asset release that corresponds to your version of Unity -- that is, Free or Pro