in those "far" countries, there s always a bit more freedom and flexibility than in europe for example, driving with or without a license/an insurance. but it s about your safety first :-). every year in india, especially, some foreigners (day renters and overlanders) get injured or killed by riding "unsafely".
for the choice of the bike, you have mainly 2 choices : enfield and honda hero style. moto cross are not very available / popular in india. if you go to se asia after india, according to the reliability and availibility of the spare parts for those 2 kinds of bikes, i would recommend you a honda hero style, as a reasonnable choice. if you buy anything in india, there will be paperwork involved, especially if you want to export (even temporarily) the bike after, depending on your nationality etc ...
see the southern asia forum and other forums for info about paperwork in india and se asia (it s been covered many times in the past)
[This message has been edited by vincent danna (edited 14 June 2005).]