Solved! Go to Solution.
Welcome to Nokia Discussions, mandlam.
You can obtain the Official Facebook App for your Nokia C6-00 through this link http://store.ovi.com/content/238066
You may also obtain it by logging in your facebook account via m.facebook.com on your phone's default web browser - the microsite should give you an option to download the application.
Try setting the system date on your phone to 10-10-2010 and try installing the app again.
Please provide feedback and I'll see what steps can be applied next.
was able to install another, tried posting the link but i doesnt appear here.
Tip: To get updates and do a complete backup on your phone, install Nokia Suite a Windows compatible computer. You may get it through this link at http://www.nokia.com/gb-en/support/product/nokia-s