Adding comments to pages
You might be confusing things which makes your question hard to answer. 

Please note that comments are not a content type, but they are part of nodes, and thus can be appended to any content type. Comment's can't be used inside the Panels module because they are part of a node (one is to import the whole node).

If you meant page rather then panel. Please make sure the comments module is enabled in modules. And then go to the 'basis page' content type and check the 'comment settings' tab (at the bottom) to see if comments are open.