I've fired up an instance of GitHub Enterprise (11.10.272) and created a repository. I've written a pre-receive hook in Ruby which I'd like to use with that repository.
GitHub Enterprise, like regular GitHub, allows the configuration of service hooks. I tried to SSH into the GitHub Enterprise server to create a hook file, but I couldn't find the repo directory. Furthemore, GitHub Enterprise's terms forbid modifying the VM, so I'm not confident this is a great approach.
It seems GitHub:FI supported hooks. The current version of the FI to Enterprise migration tool does not currently support hooks according to Migrating from GitHub:FI.