Yes, you can.
The Bloody April campaign currently under way requires a specific mod pack (which the BA hosts, J5 supplies). You might want to chat with J5_Matthias about how they go about it and if/how it can be tested (server side).
From a player testing standpoint, we were told that if: You can see The Chateau (a particular non-standard building) at a particular airport, AND you don't get a bunch of "missing graphics" errors, you've got it installed properly.
With that in mind, if you're requiring a specific Mod (or set of mods) it's probably also a good idea for you guys to bundle those into a single zip file that your users can download and use, rather than trying to make them find any / all the pieces themselves. The J5 folks have done that for the B.A. event, and that makes things *much* easier for the players to have a consistent, and correct setup.