Hi, I have to modify an existing site. English site is already done and now i have to create a Arabic site. I want to know that if i create a new template and new folder with Arabic name will it work? or i have to create a new portal and configure it as new site? need help urjecntly

First, do you want to make a separate Arabic site or do you want to "localize" the existing site. I don't have any experience, but I'd guess that you want to create another portal, as one is right to left and the other is left to right.

You can create a second portal in your existing installation for the Arabic site.