We would like to know more. Go here: https://www.youtube.com/features > Click on monetization and share the screenshot of the page that you see. This would help us look into the issue better!
If you were eligible & applied before June 1st, then you should have received an email & update in Creator Studio with more info. If your application is being held for an additional review, then you'll get a second update in the near future! Latest update: https://goo.gl/2icqfh