Mukesh Ambani retained the top spot among Indians on Forbes' annual list of the world's billionaires on Monday with an estimated worth of $21.5 billion.
The head of Reliance Industries was placed 22nd on a list headed by Mexican tycoon Carlos Slim. Ambani was ranked 19th on the list last year.
"Mukesh Ambani's fortune dropped $1 billion though he remains India's richest person and his Reliance Industries remains country's most valuable company," Forbes said.
Indian-born steel baron Lakshmi Mittal was 41st with a net worth of $16.5 billion. His fortune dropped more than $4 billion in the past year when he was number 21 on the billionaires list.
Wipro chairman Azim Premji, who gave away $2.3 billion worth of shares in his company to his education-focused foundation, made it to 91st on the list with a net worth of $11.2 billion. Premji was number 41 on the list last year.
Pharma entrepreneur Dilip Shanghvi (116), Essar Group's billionaire brothers Shashi and Ravi Ruia (131), Kumar Birla (150), Savitri Jindal and family (155), telecom tycoon Sunil Mittal (173), HCL's Shiv Nadar (182) and land baron Kushal Pal Singh (191) were among the 55 Indians on the Forbes list.
Anil Ambani, Mukesh's younger brother, was ranked 233rd and was poorer by $2.6 billion, continuing a three-year decline in his fortune.
Indian-born retail magnate M.A.Yusuff Ali, who heads the Abu Dhabi-headquartered LuLu Group, was among the 210 newcomers on the 2013 Forbes billionaires list, joining the coveted club at number 974 with a net worth of $1.5 billion.
Ranjan Pai, who heads the Manipal Education & Medical Group, also made his debut on the list at number 1107 with a net worth of $1.3 billion.
Forbes' 2013 list of the world's richest people includes 1,426 billionaires, a record number, with a total net worth of $5.4 trillion, up from $4.6 trillion in the previous ranking.
(Writing by Tony Tharakan)