In my application i need to launch ppt , xls, pdf files. i am sure, iOS Framework support to view PDF files without launching any other application, but is there any way to open ppt , xls doc , if yes please give me any pointer,
I believe, there should be some SDKs available , which can be integrated through an application and can make use of it.
If you just want to view the Office files, have a look at:
Quick Look Framework supports a lot of file formats as you can see in the links above. It is available in iOS 4.0 and later.
You can also use UIWebView to display them. See Using UIWebView to display select document types.