Recently Fastvoip started offering free calls to India Landlines and the rate drop in India mobile calling rates. Just check the free country list for Fastvoip and it mentions :
|India||United States (+mobile)|
For as low as 10Euro credit, you will get 120 freedays. In these 120 freedays you can call India Landlines phones for free. You can use the voip credit (your money ) for making cheap international calls to rest of the countries.
Calls to India mobile are at $0.007 (0.7 cent per in), after tax this rate comes around to 0.9 cent per minute. Again the rate is very competitive. I would suggest to go with this offer if you are mostly calling India landlines. But if you are calling India mobile are making a lot of calls of long duration, I would suggest you to go with IndiaLD quater calls plan.