New Delhi, Oct. 21 -- The initial public offering of Jio Platforms Ltd. was fully subscribed on the first day of bidding, keeping billionaire Mukesh Ambani's digital venture on track to complete India's largest-ever listing.

Bids exceeded the 197.5 million shares on offer within the first two hours, according to data on BSE Ltd.'s website as of 10.40 a.m. local time. The portions reserved for institutional and wealthy investors were subscribed 3.25 times and 26%, respectively. Retail investors bid for nearly 23% of the shares set aside for them.

A decade after storming into the Indian telecom market with free calls and cheap data that decimated its rivals, the company is aiming for a historic milestone with the IPO.

But unlike in the t...