JFS's shares, which listed at Rs265 ($3.18) each, fell to a low of Rs251.75 on the Bombay Stock Exchange. Its market capitalisation stood at Rs1.59 trillion ($19.25 billion) as of 10.55am UAE time.
The company was valued at $20 billion last month through a special trading session, Bloomberg reported.
Reliance has offered one share of JFS for every share owned by the company's investors.
The company's stock will have a 5 per cent circuit filter for the next 10 trading sessions. It will trade in the Trade-To-Trade segment, meaning shares can only be purchased under the delivery method and not on an intraday basis.
JFS, which owns a 6.1 per cent stake in Reliance, offers a range of financial services for consumers and merchants.
“The new entity is expected to unlock value for shareholders and give them an opportunity to be a part of a new growth platform,” Reliance chairman Mukesh Ambani said earlier this year.
“Jio Financial Services aims to provide simple, affordable and innovative digital-first solutions,” he said.
The unit is “positioned uniquely to capture the growth opportunities in the financial services sector and play a crucial role in transforming the landscape of digital finance in India”, he said in his message to investors.
India is adopting digital finance at “an unprecedented pace” and the “growth opportunities presented by financial services are remarkable and provide a strong directional support to the economy”, Mr Ambani said.
Looking ahead, the company will seek more opportunities in the digital space, Indian media cited JFS chairman KV Kamath as saying on Monday.
“We intend to be a full-service financial sector player and are already working on products," he said.
“There are some advantages of being little late to the party because you can take the advantage of riding on all the technological developments, which are already visible.”
The company will serve as an important player in India’s financial services sector, he added.
Last month, JFS and BlackRock, the world's biggest asset manager, agreed to form a joint venture to enter India’s asset management industry.
Jio BlackRock, a 50:50 joint venture combines the “respective strengths and trusted brands of BlackRock and JFS to deliver tech-enabled access to affordable, innovative investment solutions for millions of investors in India”, the companies said at the time.
JFS and BlackRock are targeting an initial investment of $150 million each in the joint venture, they said in a statement to the BSE, where shares of Reliance are traded.