Here's what may have caused country-wide outage for Reliance Jio users

Reliance Jio services were hit by a major network outage earlier today (September 17) but the telecom giant has said that it has addressed the problem, citing “minor technical issues”. Citing a source with direct knowledge of the matter, news agency Reuters has reported that a fire at a data centre of India's largest telecom carrier Reliance Jio caused the nationwide outage.
"The fire has been contained, and the servers are expected to resume operations shortly," Reuters reported.
Bharti Airtel and Vodafone Idea told Reuters that they did not experience any similar disruptions across their networks.

Earlier in the day, website Downdetector.com, which tracks outages by collating status reports from a number of sources and takes into account user-submitted errors on its platform, showed more than 10,000 Jio users have reported the issue.
While some users claimed that they faced issues related to their mobile network, others had mobile internet and broadband-related complaints.

“This morning, some Jio customers in Mumbai faced problems in availing seamless services on account of minor technical issues. The same have been resolved, and seamless services of Jio have been fully restored. We regret the inconvenience to our subscribers,” said a Reliance Jio spokesperson.
Jio leads India's telecom space with nearly 489 million subscribers as of June-end.