StaticOcclusionCullingMode Manual     Reference     Scripting  
Scripting > Editor Enumerations > StaticOcclusionCullingMode
StaticOcclusionCullingMode Enumeration

Note: This is an editor class. To use it you have to place your script in Assets/Editor inside your project folder. Editor classes are in the UnityEditor namespace so for C# scripts you need to add "using UnityEditor;" at the beginning of the script.