In 2000, Tata Cellular was a compaqny providing mobile service in Andhra Pradesh. When Birla-AT&T brought Maharashtra and Gujarat to the table,the merger of these two entities was a reality. Thus Birla-tata-AT&T , popularly- known as Batata, was born and later rebranded as !DEA

Then Idea set sights on RPG's oiperations in Madhya Pradesh which was successfully acquired, helping Batata having a million subscriber, and the license to be the fourth operator  was clinched.
in 2004, Idea(the company had by then been rechristened) bought over the Escorts Group's Escotel gaining Haryana, Uttar Pradesh(West) and Kerala — and licences for three more — UP(East), Rajasthan and himachal Pradesh.by end of that year,Four million Indians were on the company's network. In 2005,AT&T sold it's invesments to Idea.and the year after  Tata also bid good bye to pursue an independent telecom business.And Idea was left only with one promoter, the AV Birla Group.RS.2,700 crore adding Punjab and Karnataka circles. Modi's joint venture partner, Telekom Malaysia, Invested RS.7,000 crore for a 14.99% stake in Idea. Just around then idea's subsidiary, Aditya Birla Terlecom sold a 20% stake to US-based Providence Equity partners over RS.2,000 Crore