You can query posts by “Comment Counts” using the Post Grid Combo plugin. This article will show you how to query posts by comment counts.
Click on the “Query Post” tab.
Now, clicking the Choose button, you can search for “Comment Count.” Now click on it.
Then click on the Comment Count drop-down menu, enter the Comment Count value, for example, “25”, and choose the correct comparison operator.
Now your Post Grid will be updated by those posts.