The BBC reports US investment firm has interests in a number of airlines including Wizz Air, Frontier in the US and Volaris in Mexico made the order for the aircraft from the A320neo family.
However, once a number of bulk deal discounts have been factored in, Indigo is unlikely to pay the full amount.
The order came on the second last day of the Dubai Airshow and comes after speculation that Emirates was set to make a large order for the Airbus A380 failed to materialise.