I have manually moved the site content from Google Pages to Google Sites. Hence I opted out of automatic migration by Google by selecting Option 2 - Opt out of the move, and take your pages to a new location.

I setup a Redirect URL so that visit to http://nraveen.googlepages.com will  redirect to http://sites.google.com/site/nraveen.

Interestingly the sub-pages are also getting redirected. Example: http://nraveen.googlepages.com/photos is redirected to http://sites.google.com/site/nraveen/photos. And if the matching page is not available in the new site, it provides a link to Home page of the new site.

The migration options are very well thought and implemented by Google Labs team and many thanks for that.