The project is for a concession period of 35 years with an extension clause of another 10 years, the company said in a statement.
"We are happy to win Mumbai Metro-II, which is the third project that Reliance Infrastructure has won in a row. We are confident of developing this project within 5-years from the date of financial closure," Reliance Infrastructure CEO and whole-time director, Lalit Jalan, said.
The company has earlier been awarded Mumbai Metro-I (Versova-Andheri-Gatkopar corridor) and Delhi Airport Express Line.
Scheduled to be operational by 2015, Mumbai Metro II would provide a link between Navi Mumbai and the western suburbs, connecting Charkop in the north to Bandra and then to Mankhurd in the east.
The total length of the project is 32 kilometres which would have 27 stations en-route.
The project has been awarded by Mumbai Metropolitan Region Development Authority through an international competitive bidding process.
Reliance Infrastructure has won the project in consortium with SNC Lavolin Inc, Canada, and Reliance Communication.