NCDs are unsecured loans to a firm with no provisions to exchange debt for corporate stock.
The deal will give India's largest conglomerate indirect stakes in seven airports in India and abroad.
The FY13 fourth quarter (Q4) earnings, however, fell short of analysts' expectation, as debt was still high at Rs 21,730 crore (Rs 217.3 billion), with much of the targeted non-core sales done.