go to the bsnl office in your area and ask them for a demo of EVDO at your house. they will come and connect it with ur pc. If you get good speeds of about 2mbps or more, then go for it, although they boast of much higher speeds. at 750 pm the EVDO unlimited is the best with NO FUP!
you can also get BSNL 750 unlimited plan, at 512kbps unlimited no FUP.
or go with the airtel plan, if you dont find any other plan. you can also see if there are any local cyber cafes which provide internet services. in some areas the cyber cafes have really cheap plans.