If there is no content on Category pages, should I noindex them?
Hello @asif.khan Welcome to our community
Secondly, I do not recommend to index categories and tags pages because of content replication between post pages and categories or tags pages so the best practice is that simply index only post pages and noindex (Exclude from Sitemap as well) categories and tags pages and this scenario allow if you are running blogs only.
Siraj Bhai thanks for replying.
How to Exclude them from Sitemap who already ranked (categories and tags pages).
If you’re already ranked categorises or tags pages and getting traffic over there and if the traffic is excessive more than 100 visits then let it be and don’t disturb then its fine, If less than <100 then in the Yoast SEO plugin there is an option to exclude taxonomies and tags pages under these sections in the plugin.
Thanks for support Siraj Bhai