"To reflect this wave of transformation, we decided that we needed to embrace change in this year's 40 Under 40. We needed to go bigger -- and search more widely," it said.
This year's list includes 40 influential people under 40 years of age in five categories -- finance, technology, healthcare, government and politics, and media and entertainment.
"They say data is the new oil -- and when it comes to Reliance Industries, India's largest company, that's literally the case," Fortune said, adding the 47-year-old conglomerate amassed a fortune in petrochemicals before dominating the country's mobile connectivity market with Jio, a low-cost wireless carrier which debuted in 2016.
Reliance is a family business. Akash joined the company in 2014 after receiving an economics degree from Brown University. Isha joined a year later, following stints at Yale, Stanford and McKinsey.
"As Jio board members, they helped seal the company's recent megadeal with Facebook -- $5.7 billion for a 9.99% stake -- plus major follow-on investments from marquee tech titans like Google, Qualcomm, and Intel. The flurry of investments lent the business an eye-popping $ 65 billion private valuation," it said.
The Ambani scions, it said, lead enviable lives, "attending private concerts featuring Beyonce, partying with buddies Priyanka Chopra and Nick Jonas, living it up in a 27-story residential skyscraping pleasure palace in Mumbai." "When the glam siblings are not basking in unfathomable luxury, they're training -- along with their younger brother, Anant, 25, a more recent addition to Jio's board -- to take on their father's empire. A major proving ground will be e-commerce," it said.
Recently, Akash and Isha helped launch JioMart, a venture that aims to challenge Amazon and Walmart's Flipkart for command of India's massive and fast-growing online shopping market. "Hey, even heirs have to earn their keep." Regarding Raveendran, Fortune said he has shown the world that it really is possible to build a massively successful online education company.
"Byju's, as the company is known, has become India's biggest education technology company, helping millions of students prep and study for the most important exams of their lives while teaching them a thing or two about core topics like mathematics and science," it said.
Since its founding in 2011, the red-hot education startup has raised over $1 billion and is now worth more than $10 billion.
"Raveendran will need that cash as he aims to expand Byju's into new countries like the United States and the United Kingdom," Fortune said.
Though the education business tends to slow down in the summer, Raveendran has been keeping busy.
In August, Byju's bought the education technology startup WhiteHat Jr for $ 300 million.
Manu Kumar Jain, managing director of Xiaomi India, also features on the list.
"Jain knew nothing about smartphones when Chinese giant Xiaomi tapped him in 2014 to build its India operations from the ground up. But he did know a thing or two about startups," Fortune said.
The last company he founded, Jabong, was a fashion e-commerce player that was sold to Flipkart.
In his quest for knowledge at the start of his new gig, the executive regularly carried between 30 to 40 smartphones in his bag, testing out features and checking out competitors.
"His (literal) heavy lifting paid off: Under Jain, Xiaomi overtook Korean colossus Samsung to become the smartphone leader in India in just three years, bolstered by a strategy to act more like an Indian company," it added.