Jio has been teaming up with other American tech companies such as Microsoft to offer an enhanced suite of services to small businesses. Its current offerings include high-speed internet, cloud storage, payments and even products from its vast retail supply chain.

This is not Facebook’s first foray into the Indian market. Several years ago, it tried to offer free internet connectivity to Indian users in a program called Free Basics. But that initiative hit snag after snag until it was banned in the country in 2016. Regulators decided that companies could not offer free internet services that favored some companies over others.

More recently, Facebook has been at loggerheads with the Indian government over WhatsApp. The government has demanded that WhatsApp change its encryption to trace messages back to their source, which WhatsApp has refused to do. At the same time, regulators have repeatedly stalled WhatsApp’s request to offer a payments service to its Indian users.

Jio was founded by Mukesh Ambani, an industrialist who is India’s richest man. It transformed India’s technology scene when it hit the market in 2016 by offering free calls and ultracheap 4G data to Indians who were previously stuck with high prices and slower 3G connections from the existing carriers.

Since then, Jio has become India’s largest carrier by number of subscribers, with nearly 400 million lines. It has helped drive India’s mobile internet costs to the lowest in the world, with virtually unlimited data and calls costing just a few dollars a month. The price war it began has also hobbled India’s telecom companies, driving many out of business.

Jio has ambitions to take on Amazon in e-commerce, run data centers, provide fiber internet to homes and businesses and set up new services like tele-health and distance learning.

But Mr. Ambani incurred enormous debt to build the telecom business. Those costs have been subsidized by other parts of Reliance Industries, which is also India’s largest retailer, its biggest producer of polyester and one of its biggest energy companies.