Hey Atul,
To register your books simply visit the following URL:
http://www.manhattangmat.com/access.cfmThe six CAT exams that you get access to are the same no matter what Strategy Guide you register. This is because all the CATs pull questions from our question bank of over 1000 questions. We give you access to CATs in sets of six. If you complete all six and want to do more, simply call or email us and we can reset your tests. However, once we do this, all of your previously answered questions will return to the question bank and you run the risk of seeing them again during your next set.
As far as the eight Question Banks, each Strategy Guide comes with its own so you'll want to register all of your books.
Let us know if you have any other questions.
Best,
Matt Mapplebeck
Student Services Associate
Manhattan GMAT