Hangout to Hangout calls are free, however, if you are using Hangout Dialer to call India the rates are mentioned below.
Country/Region Rate per minute CAD
India - Landline 2¢
India - Mobile 2¢
India – Andhra Pradesh – Landline 2¢
India – Andhra Pradesh – Mobile 2¢
India – Chennai – Landline 2¢
India – Chennai – Mobile 2¢
India – Hyderabad – Landline 2¢
India – Puducherry – Landline 2¢
India – Tamil Nadu – Landline 2¢
India – Tamil Nadu – Mobile 2¢
That's 2 cents/min.
The rate will change based on the country you are calling from.
You can check rates for different countries by signing into Gmail-Hangouts Phone Icon-View All Rates