Which Indian International Airport is slated to be the biggest in India?

Indira Gandhi International Airport in Delhi was expanded and modernized with the opening of Terminal 3 in 2010, making it India's largest airport by terminal size and passenger capacity. The airport can handle over 60 million passengers annually and features world-class infrastructure. While Mumbai's airport is also very busy, Delhi's T3 terminal made it the largest in terms of physical infrastructure and capacity. The airport serves as the primary international gateway to India and is a major hub for international carriers. The question uses past tense 'was slated' referring to the expansion plans that were completed.