After his father Dhirubhai Ambani's stroke in 1986, he began to make a name in the business world. Anil oversaw the daily management of financial transaction administration at Reliance. After Dhirubhai's death in 2002, Anil Ambani and his elder brother Mukesh Ambani co-led Reliance. However, the arguments over control led to their breakup in 2005. While Mukesh bought the petrochemical and oil industries, Anil bought new companies in the financial services, energy, and telecommunications sectors.
Anil Ambani entered various sectors including infra etc. but got limited success. His attempt to set up a gas-based mega power project in Dadri, Uttar Pradesh suffered a major setback when the Allahabad High Court canceled the land acquisition in 2009. Deals with Adlabs and DreamWorks also failed .
The financial situation worsened as the debt of his telecom company, Reliance Communications, started to increase. The business filed for bankruptcy in 2019. In the same year, RCom had failed to pay the Indian division of the multinational company Ericsson AB ₹550 crore, and Anil Ambani was on the edge of going to jail. Mukesh Ambani stepped in at the last minute to save his brother from going to jail.
Anil Ambani's troubles grew worse when Chinese banks sued him in a London court over a $680 million loan default. Loans were given to RCom in 2012; Anil was allegedly required to provide a personal guarantee for these loans. Ambani argued in court that the correspondence he had sent was only advisory in nature. The legal matter is still underway. In 2021, Reliance Capital also became insolvent due to loan defaults of ₹24,000 crore.