As part of the offer, RCom customers would be able to avail 24 hours of free local and STD calling across the Reliance network on March 28, RCom said in a statement today.
The one-day offer will be available to all new and existing Reliance customers across CDMA, GSM and Hello (fixed wireless) services, it added.
"We are truly humbled by the trust conferred on us by our customers. This is a small gesture to appreciate and express our gratitude to our 100 million customers -- the biggest such offering ever made available anywhere in the world," RCom President Mahesh Prasad said.
Earlier this month, RCom became India's second operator and the fourth operator globally to serve over 100 million customers in a single country.
The company has set a target to achieve the next 100 million customers on its wireless network in 1,000 days.