Abidemi Kusimo

You can make use of category popular tag to display most used tag on your blog. This will give list of frequently used tag anywhere you place the shortcode or funtion in your theme.
For example [popular_category_tags count=10 type=”popular-tags” category_id=”1″]. 
You can also call this function from your theme file: cush_category_popular_tag() for basic output.
When using the shortcode type is required. category id, count is not required. if no category id suplied, the plugin will default to current post category available. 
For example [popular_category_tags type=”popular-tags” ].
You can find category tags options under Settings page 
Settings -> Category Tags
Credit : (https://wordpress.stackexchange.com/questions/261617/display-most-popular-tags-of-category)

Category Popular Tags

Display popular tags on achieve/category page of your theme using sortcode or by calling a function.

DolarPatel

This WordPress plugin adds custom post type widgets or post widget.
You can filter by registered Custom Post Type.
<h4>Key Features</h4>
<ul>
<li>Title – description that appears over the list of recent custom posts.</li>
<li>Post Type – if selected, filter by a custom post type. (e.g. post).</li>
<li>Number of posts to show (at most 15) – enter the number of posts to display.</li>
<li>Show post view – if selected, this box causes a count of the number of view for each post.</li>
<li>Show post comment – if selected, this box causes a count of the number of post comment.</li>
<li>Show post date – if selected, Display the post publish date.</li>
<li>Show post image – if selected, Display the post featured image.</li>
<li>Show post Excerpt – if selected, Display the post Excerpt.</li>
<li>Show post category – if selected, Display the post category.</li>
</ul>

WordPress Popular Post

This WordPress plugin adds default custom post type widgets with post view , comment count etc.

Category Popular Tags vs WordPress Popular Post