On Awake, Set System Tag array to 100?

I need to create 100 tags in the tag manager on awake with script

Any Ideas?

You cannot add tags to the tag manager at runtime. You likely can write an editor script to add them at edit time. Here is an answer that talks a bit more about the issue and has a few suggestions:

http://answers.unity3d.com/questions/46037/add-tags-during-runtime.html