Sean Hayes

Comments On is a plugin that adds a column to the “All Posts” or “All Pages” view in the Admin dashboard. The column will display one of three options for the related post/page: “open”, “closed” or “registered_only”.
Now, quickly and easily, without having to click “Quick Edit” or “Edit” for each post you can find out which posts/pages can accept comments and which can’t.
It is an ideal companion for the Comment count column alerting you to content that hasn’t any comments. Or it can highlight any posts/pages that might not be enabled for comments.

Comments On

Comments On adds a column to the "All Posts"/"All Pages" view in the Admin dashboard showing the status of comments.

Sergey Biryukov

Adds parent comment ID meta box to a comment editing page. Use to make existing comments threaded.

Edit Parent Comment ID

Instead, I advise you to use this plugin Change Comment Parent



New alternative to this plug-in

Adds parent comment ID meta box to a comment editing page.

Comments On vs Edit Parent Comment ID