Hello Guys , I am making a video game website and I want to know how I can add data to the website...Copying from other site and rewriting ?
You should never copy and rewrite material from other sites unless you have their permission to do so. For example, you can get articles from ezinearticles, but you may not edit those. Or, you could get PLR articles which you can edit in any way you like. If you don't own the copyright to the original articles or have permission from the person who does, you don't have the right to create derivative / rewritten versions of it legally (assuming you're in the US from the site in your sig, but that's also true in quite a few other countries).
Why not do your original contents? If you are familiar with video games, I'm sure you can write about them. If you don't write well, you can always hire someone to write for you.