Ckeditor plugin

I want to add a youtube or mediaembed plugin in ckeditor. I have added the plugins in the plugins folder of ckeditor but it is not showing up. I know we have make changes in ckeditors config file but I am unable to find a proper cofig file. Can anyone help me in getting this?

In my case problem was Case in plugin directory name, it was:


and should be:


Check Your console with javascript errors.