India's roughly $150 billion outsourcing sector generates about three quarters of its revenue from the United States.
Critics say the programme, launched 10 months ago in India in collaboration with operator Reliance Communications, violates principles of net neutrality
Poor disclosure among India-listed firms is a turnoff for foreign investors.
IndiGo was set up in 2006 by businessman Rahul Bhatia and Rakesh Gangwal, a former CEO for US Airways Group.
India's tax officials, long the scourge of foreign investors, are under government pressure to avoid aggressive claims against overseas funds.
The rupee has fallen more than 2 per cent against the dollar since the yuan devaluation
India's mutual funds are seeing a surge in stock investments from the hinterland as growing ranks of provincial retail investors help drive a two-year long rally.
An estimated $344 billion has been illegally removed from the Indian economy between 2002 and 2011
India imposes restrictions on how much money its citizens and companies can invest abroad
Investor lobbies and tax lawyers estimate the bill for international funds and banks could be as high as $8 billion
Sebi has long struggled with balancing the needs of small investors and those of the market.
The move will likely attract more retail investors.
The policymaker said the RBI had not reached the point where specific actions were under consideration.
Sebi also approved new delisting rules.
Sebi has asked clearing houses to establish separate funds for all segments of the market including equity, debt and currency.
The drive against insider trading comes after SEBI last year received enhanced investigation powers from parliament, including the ability to monitor call records.
Both companies can now complete the deal.
The Securities and Exchange Board of India (SEBI) unveiled new proposals, broadening the scope of who can be held liable for insider trading violations.
The market regulator is wielding an unprecedented level of control over how mutual funds operate, delaying new launches and dictating investment strategy, frustrated insiders in the embattled industry say.
It was put on hold in 2008 after the global financial crisis.