Kavita --
For a basic overview, start with the main Oral Cancer Foundation site. There are links from the
home page on diagnosis (including tests), treatment, staging, etc. That will give you good information to serve as a starting point for e-mails or telephone conversations with your dad and his doctors. You can, of course, ask anything on these pages, and someone should have the answer.
In addition, there have been several posters here with family members treated in India. If you search for
India in the search box in the upper right of each forum page, you'll find most of them. You can read their experiences, then go to their profiles and send them e-mails with any specific questions about their relative's treatment.
I know it must be difficult being so far away at this time. Good for you for wanting to learn all you can to help your dad.
All the best,
Leslie