Depends on your origin for sim availability, and length of stay. Lebara offer roaming in india, and can be had on a 30 day contract. We used to get really good prices, but for now, a currently available deal is 15gb per month, unlimited calls and texts, on a 30 day contract for £1 per month for up to 7 months, but I doubt you could use it over there for more than 90 days out of a rolling 180