Is it possible?

Is it possible to add an url in more than one category in dmoz?
Thanks

Yes and No.
You can't add an url to any category, only editors can do so. You can only suggest a site.
In a few cases sites might be listed in more than one category. But it is always up to an editors decission to do so.
All you can do is suggest the site to the ONE best category.
If your site is in more than one langauge you may suggest it under all of these languages.