I want to use Microsoft office 2010 in my iPad. How it is possible

Have a look at the following:

http://itunes.apple.com/sg/app/quickoffice-pro-hd-edit-office/id376212724?mt=8&l s=1

http://itunes.apple.com/sg/app/office2-hd/id364361728?mt=8&ls=1

http://itunes.apple.com/sg/app/documents-to-go-premium-office/id317107309?mt=8&l s=1

http://itunes.apple.com/sg/app/polaris-office/id513188658?mt=8&ls=1

Apple has similar apps. They offer Keynote (like PowerPoint), Pages (like Word), and Numbers (like Excel).

All three of these apps can read and write files like their Microsoft counterparts.

You can find these apps in the App Store.

There are also third party apps. I use Documents to Go and it interfaces very well with the Word on my computer. That one also comes with a separate desktop program to allow syncing without going thriough iTunes.