If your specific microphone model is not available as a Mic Mod EFX microphone profile, you can use one of the 'Generic' models that matches your microphone's build characteristics. It's up to you to research the design of your own microphone to pick the best match with one of Mic Mod EFX's 'Generic' mic profiles.
Alternatively, if your microphone's manufacturer is available as a mic category but your microphone model is not, you may find one of the other models by your microphone's manufacturer is of a similar design to your own. Again, it's up to you to do the research about this.
In general, choosing a source mic option that does not exactly match the mic you're using can still lead to good sounding results. It just won't be as accurate of a model. Let your ears be your guide!