Reliance Industries Chairman Mukesh Ambani said that India's economy to treble in size to a $7-trillion economy from $2.5 trillion in coming years and feels that currently, India is the the biggest investment opportunity in the world.

Speaking at an event in Mumbai, Mukesh Ambani said Reliance took a contrarian bet to invest Rs 3.5 lakh crore in India and that has paid off handsomely.

"A few years ago, the fashion in India was to invest abroad," Ambani said.

"If you don't invest abroad, you are left out. We took a contrarian bet and invested over Rs 3.5 lakh crore in a single bet in India. The significant portion of that investment is in Jio", he said.

Reliance Jio's entry in the telecom sector had triggered an intense price war battle, making the relationships between the sector biggies a little tense, reffering to which Ambani further said, "The Prime Minister's vision is backed up by the concrete action in terms of open, transparent and fair policies where even some ragging by incumbents is tolerable and fun and we can still be friends," he said to an audience that included Bharti Group chairman Sunil Mittal, Aditya Birla Group chairman Kumar Mangalam Birla and Vodafone India CEO Sunil Sood.

Earlier this year, Mukesh Ambani had also expressed his confidence in the Indian economy. He said that the Indian economy in another 10 years would rank among top three economies of the world.

Ambani said, "I believe Indian economy will grow to $7 trillion in next 10 years." Emphasising the importance of digital India, Ambani said, "Data is the new oil and India possesses its abundance." He said that the firms need to provide ubiquitous data to every Indian at an affordable prices.

"Data is the oxygen to digital economy", he added.

He said, "4G coverage in India will become larger than 2G coverage in the next 12 months". Highlighting the increased use of data in the country, he said that India has potential to lead fourth industrial revolution as India does not need to import data.

He also mentioned that how India has become the largest telecom market in the world.