World Ranking : 742
Reliance Communications Limited is a major Indian telecommunication company headquartered in Navi Mumbai, India. It is the 16th largest operator in the world with more than 128 million subscribers. RCOM, founded by Dhirubhai H Ambani (1932–2002), is the flagship company of the Reliance Anil Dhirubhai Ambani Group. The Reliance Anil Dhirubhai Ambani Group currently has a net worth in excess of 64,000 crore (US$13.6 billion), cash flows of 13,000 crore, and a net profit of 8,400 crore. The Equity Shares of RCOM are listed on Bombay Stock Exchange Limited and National Stock Exchange Limited. The Global Depository Receipts and Foreign Currency Convertible Bonds are listed on Luxembourg Stock Exchange and Singapore Stock Exchange respectively.
Main subsidiaries:

Reliance Telecommunication Limited (RTL):
In July 2007, the company announced it was buying US-based managed ethernet and application delivery services company Yipes Enterprise Services for a cash amount of 1200 crore (the equivalent of US$300 million). The deal was announced of the overseas acquisition, the Reliance group has amalgamated the United States-based Flag Telecom for $210 million. RTL operates in Madhya Pradesh, West Bengal, Himachal Pradesh, Orissa, Bihar, Assam, Kolkata and Northeast, offering GSM services.

Reliance Globalcom :
RGL owns the worlds largest private undersea cable system,[4] spanning 65,000 km seamlessly integrated with Reliance Communications. Over 110,000 km of domestic optic fiber provides a robust Global Service Delivery Platform, connecting 40 key business markets in India, the Middle East, Asia, Europe, and the U.S.

Reliance Internet Data Center (RIDC):
RIDC provides Internet Data Center (IDC) services located in Mumbai, Bangalore, Hyderabad and Chennai. Spread across 650,000 sq ft (60,000 m2) of hosting space, it offers IT infrastructure management services to large, medium and small enterprises. It is one of the leading data center service provider in India and provides services like colocation, managed server hosting, virtual private server and data security. It has launched cloud computing services, offering product under its infrastructure as a server (Iaas) and software as a service portfolio, which enables enterprises, mainly small and medium, a cost-effective IT infrastructure and application on pay-per-user model.

Reliance Digital TV:
Reliance Big Tv launched in August 2008 and thereafter acquired 1 million subscribers within 90 days of launch, the fastest ramp-up ever achieved by any DTH operator in the world. Reliance Big TV offers its 1.7 million customers DVD-quality pictures on over 200 channels using MPEG-4 technology.