MaximeB

This plugin will check if there are some hidden meta tags with noindex and warns the author of the article. The warning is only visible for the author of the post, or the admin(s).
Features :
<ul>
<li>Check the content of a post and detect the presence of meta tags with robots/noindex in it.</li>
</ul>

Better noindex

Warns the author or admin in case of <meta name="robots" content="noindex"> hidden in a post.

amodoke

This plugin lets you Noindex Nofollow All Posts in a category. 
Simply go to Posts > Categories, and click on any category’s EDIT link. 
There you can just “tick” the relevant option you need. 
The plugin will then add a “noindex” or/and “nofollow” line in all posts in that category.
A few notes about the sections above:
<ul>
<li>DigitalChef.in – Madhu Ramrakhyani</li>
<li>This plugin lets you Noindex Nofollow All Posts in a category.</li>
<li>“3.0” is the lowest version that the plugin will work on</li>
<li>“4.7” is the highest version that you’ve successfully used to test the plugin. Note that it might work on 
higher versions… this is just the highest one you’ve verified.</li>
</ul>

NoIndex NoFollow  All Posts

This plugin lets you Noindex Nofollow All Posts in a category.

Better noindex vs NoIndex NoFollow All Posts