Two custom-made B777-300ER aeroplanes will be used to fly Prime Minister Narendra Modi and other top dignitaries from July 2020

Unlike norms, these planes will not be operated by Air India pilots and will be maintained by Air India Engineering Services Limited (AIESL), a subsidiary of the Indian national carrier. 
Here are some facts about the new aeroplanes, as gathered from multiple sources. 

1. The two Boeing 777 aeroplanes will be used to fly the Prime Minister, President and Vice-President.

2. Just like the B747 aircrafts, B777 will have the call sign 'Air India One'.

3. The new wide-body aircraft are being manufactured and customised at Boeing's Dallas facility in the United States.

4. The aircraft will be equipped with missile defence systems that will make it as secure as the Boeing 747-200B used by US President Donald Trump.

5. This is the first time an Indian aircraft will be equipped with SPS (self protection suites), which can effectively jam enemy radar frequencies and divert heat-seeking missiles.

6. The aircraft will also feature Large Aircraft Infrared Countermeasure system (LAIRCM), a state-of-the-art missile defence system, purchased along with SPS for $190 million.

7. Unlike Boeing 747 aircraft (used to fly dignitaries), the B-777s will be operated by pilots of the Indian Air Force (IAF) and not of Indian national carrier.

8. Apart from other features, the aircrafts can store food for over 2,000 people.

9. The aircrafts can withstand grenade and rocket launcher attacks.

10. Lastly, the new aircraft will arrive in India by July, 2020.

The President is designated VIP 1, The Vice President, VIP 2, and The Prime Minister, VIP 3 while on an official tour or journey to a country.