Reliance Jio is offering free unlimited data for first three months with 4,500 minutes of voice calls.
The Lyf smartphones are available in Delhi-NCR, Bengaluru, Mumbai, Chennai, etc.
The Mukesh Ambani-led company is likely to launch the network commercially now.
Jio is expected to disrupt the market and its low cost offerings may hurt other telecom companies such as Airtel, Idea, Vodafone, etc.
ET quoted some store executives saying the 4G cards were available since last week.
Jio's strategy and planning head Anshuman Thakur told ET that the company was awaiting the integration of spectrum that it expects to get from the sharing-and-trading pact with RCom.