WordPress.org

Redirect Category will perform HTTP 301 redirections on requests to posts belonging to categories of your choice.

Most important requirements.

1. Permalinks structure of both the sites should match.
2. The corresponding posts should be present on the destination domain.

Before you select existing categories for redirection, it is recommended that you create a test category and study the functionality of the plugin to make sure it meets your specific requirement.

Once turned on, it is recommended to keep the plugin turned on till all relevant search engines have updated their indexes for your redirected posts.