If you have iOS 4... See Here...
Connect to iTunes on the computer you usually Sync with and “ Check for Updates “...
If an Update Appears Install it... if not... you are up to date for your particular Device...
See the Using iTunes Section Here...
4. iPad Support
a. Updating Your iOS to Version 6.0.x from iOS 5
Tap Settings > General > Software Update
If an update is available there will be an active Update button. If you are current,
then you will see a gray screen with a message saying your are up to date.
b. If you are still using iOS 4 — Updating your device to iOS 5 or later.
c. Resolving update problems
The beta didn't mysteriously appear on your phone... If you are not a registered IOS developer, you had to obtain it from a pirate source and hack your phone to install it.
You can't get any support for unauthorized modifications of your device in this forum. You're on your own.
FYI, this is the iPhone, not iPad forum. Why did you post here?