The mobile user base is expected to grow to 815 million this year, from 755 million connections in 2013, it said.
"The mobile market in India is going through a rough patch, where voice average revenue per user (ARPU) is falling very fast, and the increase in data ARPU is not able to fully compensate for the decline," Gartner Senior Research Analyst Neha Gupta said in a statement.
She added that if the prevailing market conditions do not change in the Indian mobile market, India will account for 12 per cent worldwide mobile connections.
However, the country will account for just 2 per cent of worldwide mobile services revenue, she said.
Gartner said one of the biggest challenges faced by Indian mobile operators is the growing appetite for over-the-top (OTT) voice services, driven by the explosion in personal connected devices like smartphones and tablets.
"Mobile broadband provides a substantial revenue opportunity in India on the back of low fixed line broadband penetration. Packing and selling mobile broadband in small and affordable chunks is critical to uptake," Gupta said.
Another area of opportunity, according to Gartner, is focusing on innovative mobile apps that help increase loyalty of the consumer.
"These could go beyond the popular category of social and video apps to include utility apps like shopping apps. Apps that can provide high user-experience on low tech phones are likely to have higher traction than others," Gartner said.
Operators that engage with popular content and service brands and bundle their apps and services with their data plans will drive consumer interest in mobile broadband, it added.
As per the Telecom Regulatory Authority of India, there were 910.16 million mobile phones, and 938.34 telecom service (including landlines) users in India at the end of May 2014.
Active wireless subscribers on the date of Peak VLR in May, 2014 were 790.52 million, it added.