What exactly do you want to do? Do you want to stream movies from Netflix? Or copy a DVD that you already own and watch that movie on the iPad. Or purchase a movie from the iTunes Store? Or watch a movie that you've taken with the iPad's camera? I notice that you posted this in the Hacking section. Is your iPad hacked and, if so, is that the problem you're experiencing?
Give us some more details and we'll do what we can to help
You can download number of video players from the app store, but you are better to download Handbrake, which is free for mac and windows, and convert your videos to mp4 format. They can then be imported into iTunes and synced with your iPad.