Hi Krishna, I hope you're enjoying your time in India! Good to see that you're able to use data. Which provider network are you connected to? In India there are a few that you can choose: Airtel India, Loop Mobile India Connected, Mahanagar Telephone Nigam Limited, Reliance Jio Infocomm Limited, Vi and Telenor India Communications Private Limited. It's possible that not all networks allow phone calls and SMS. Please manually select to another network to see if it works. I'd love to hear from you!