Getting iphone is important for its Internet features. So lets look at what plans these mobile companies are offering.
Both vodafone and Airtel the official partners for iphone don't have unlimited data plans for iphone.
Take a look at Vodafone mobile plans which are specific for iphone. None of them provide unlimited data.
About 3G here is what they are saying about it
Select features and services are currently available in India. 3G features can be used on 3G networks while roaming aroad.
Above text was taken from Vodafone site and the spelling mistake was in the site. Seriously that is your answer to 3G service. Use it when you are roaming abroad.
Airtel is not advertising the iphone on its site where as Vodafone has a big banner on the main page.
I really would like to know how many people would by an iphone at twice the price of that in USA and half the features. And also how many would pay more for going over the limited data usage plan.
My suggestion is to get an jail broken iphone in black market for 15000 Rs for the iphone 2G or 27000 Rs for the iphone 3G.
And getting an bsnl postpaid Plan 225 and you get unlimited data for 450 Rs. It would be cheaper than going with the official iphone partner in India.