How to deal with categories duplicate to tags?

I took over a website and I'm cleaning up things. I noticed there are a dozen categories and tags with the same name, i.e. there is a category and a tag both with the name "cats". I have already no-indexed tags to prevent bloat, thin content and duplicate content. My question is how to solve that issue completely? Should I redirect the tags to the respective category? My guess is that a redirection would work. Thanks in advance!