Yes but won't be a very useful exercise. Because, you will have to purchase a new map of India, install it (provided you have an SD card slot) or install it to the hard drive (provided you have the space) and switch the maps. Very easily said than done.
Most important of all, I do not think, Tom Tom offers a map of India. It would be best to buy a cheap one that comes with mapmyInida maps pre-installed. My one suggestion would be look for a GPS where you can navigate by latitude and longitude input as an option. Since most towns/rural areas do not have street/Avenue intersections, locating your destination in Google and feeding that lat/lon to your GPS would enable you to use your GPS far better in those conditions.
If you travel in Inida with a GPS on Lat/Lon inputs, I would definitely like to hear your experience. Send a Personal Message on [email protected]
please. Check out Mapmyindia.com. Garmin seems to have India maps and GPS in the Rs. 8000/- range. Costlier compared to US prices though.