Upvote:1
Technically, there is no such thing as an international SIM card. They are always registered in a country and just the roaming fees are somewhat cheaper than the average mobile phone provider's ones.
If you only go to India than you should definitely get an Indian prepaid SIM card.
I do this in any country that I stay more than 2-3 days in and it has proven to be the best solution.
I have not been to India, but I don't see why it would be different there.
In most countries, SIM cards cost anything between $0.30 and $5. They often come with credit already. Local phone calls and txt are usually extremely cheap and you can buy an for a few bucks internet package as well. I never paid more than $10 to $20 for a month of lightly phone + txt and heavy data usage.
As soon as you are there, just head to the first mobile phone shop you see and explain to them what you want. Might be a good idea to do this in the airport already, as chances to find someone who speaks proper English are higher and this makes negotiating technical details much easier. Also airport shops don't tend to rip tourists off too much.
You might need to show your passport, so they can register the number for you.