Sorry I have never used Telerik. But I used to integrate ads (inmobi) into my hybrid app using Monaca. I found a step-by-step demo for this integration in the link below: http://docs.monaca.mobi/en/sampleapp/tips/inmobi/
I hope you can use it as a reference. Cheer.
Update: The above link is removed. So, I added the new link for How to integrate AdMob into Cordova app.