Welcome to the Jungle, where there is no clear path. You will have to find a path to your success. I don't have any documentation for OAT. You can go through the Rules which is there in the beginning of this thread. Please note that I am not a Guru and I am also learning like you. This OAT tool just downloads the Options Chain from the NSEindia.com site and Gives a perspective. So for you to have the basic idea on the Options Chain, you should understand what is Open Interest (OI) , Change in Open Interest (COI), Volume, Implied Volatility. These parameters are pretty much covered In my rules, which should give you a basic knowledge on Options Chain. Advanced Knowledge will only come through experience and continuous observation of the Options Chain. If you discover anything new, you are most welcome to share it with us. Please note that the most important thing is that the Rules are based on MY OWN Interpretation of the Options Chain data and I don't claim that it works. So consider OAT as just a tool which shows you the Options Chain data for the Index or Stock.
Regards
Vaib