Hello Himamshu,
I believe that this is the result of a major update made to the platform around nine months ago, which included the removal of the ITTO questions option. Full information is available in the following thread:
www.project-management-prepcast.com/kune...pmp-simulator-deluxe
In my personal opinion, with a view to achieving a good result in the PMP exam, you're not missing out on crucial content. While knowledge of ITTOs in the real world can make you a more fully rounded project manager, the current PMI exam doesn't seem to expect candidates to have memorised all the ITTOs like they did in the past.
All the best with your study and preparation,