Currently Being ModeratedNov 19, 2012 6:27 PM (in response to Hemantgavande)
Connect to the computer you use to sync with, when iTunes opens click on the name of your iPad under DEVICES in the far left frame, move to the Summary tab to the right and click on Update.
Currently Being ModeratedNov 19, 2012 6:59 PM (in response to Hemantgavande)
If it's an iPad 1, it will update to iOS 5.1.1. Newer iPads will update to iOS 6.0.1.
iOS 5: Updating your device to iOS 5 or Later
How to install iOS 6
iOS: How to update your iPhone, iPad, or iPod touch
If you are currently running an iOS lower than 5.0, connect the iPad to the computer, open iTunes. Then select the iPad under the Devices heading on the left, click on the Summary tab and then click on Check for Update.
Tip - If connected to your computer, you may need to disable your firewall and anitvirus software temporarily. Then download and install the iOS update. Be sure and backup your iPad before the iOS update. After you update to iOS 6.x, the next update can be installed via wifi (i.e., not connected to your computer).