Currently I working in publishing projects. I need to create a automated template in word document. For instance: italic word should have tag surround the text. Please advise how to proceed?
MS Word lets you create HTML output, but it is very messy. There are several online tools for converting this "messy output" and some commercial tools as well.
I have used the free tool wordoff with some success https://wordhtml.com/
As an alternative, you can cut/paste the formatted text into an HTML editor online (wordpress, etc). Maybe you can paste it into a desktop HTML editor and see if the source view has the tags you need. Often that can clean up your code and leave the italic and bold tags. But you still have to do some extra cleaning after.
You need to be more clear about why you need your source to be HTML. Is it going to be an epub file? Or some other format?
Generally, I avoid trying to use HTML output from MS Word. It is very messy. It sometimes is just easier to just copy the text into a decent html editor and insert the tags yourself.