Krishna,
I too am sorry to hear about your father and hope that his treatments go well.

Each person's cancer is, in a sense, unique to that person. While the details of others' experiences may help you to get an understanding of the range of treatment, ultimately you will be depending upon the expertise of your doctor(s) to devise a treatment that best meets your father's needs.

I know very little about what treatment options are available to you in India but I would suggest that you look for a hospital that provides a team of specialists who decide together on the best course of treatment. In the comprehensive cancer hospitals in the States, such a team would typically include at least an earn, nose and throat surgeon, a radiation oncologist and a medical oncologist. Look for a hospital with such a team-based approach as this will likely result in the best treatment plan.

Second, I would suggest that you get a second opinion from a second hospital to make sure that the recommendations from the first are appropriate.

If your father is going to have radiation, be mindful that the radiation should start within 6 weeks of the surgery in order to be of maximum effectiveness. It is also a good move to see a dentist who is familiar with radiation treatment for oral cancer before the radiation begins. This will enable your father to keep as many teeth as possible and to avoid complications to the teeth from the radiation.

A number of studies have indicated that combining chemotherapy with radiation is more effective than radiation by itself. You should check the news section of the Oral Cancer Foundation web site for details of this. See, for example,
http://www.oralcancerfoundation.org/news/story.asp?newsId=1184
You may want to ask your father's doctors about this.

A number of people on this forum had a feeding tube installed before they started their radiation treatments. Because radiation can be so difficult and adversely affect swallowing, a PEG or feeding tube can alleviate the difficulty of keeping your father nourished and hydrated.

Others on the board may have additional suggestions that I've overlooked. Hope this is of some help. Best wishes, Sheldon