What documents are needed for my Thai national minor son to travel from India to Bangkok?

To travel from India to Bangkok with your Thai national minor son, you will primarily need his Thai passport. It's highly recommended to obtain a notarized consent letter from his Thai mother, permitting him to travel with you, especially since he has been residing in India for several years. While not always required, this letter can help avoid potential issues with the airline or immigration officials. Additionally, carrying the child's birth certificate and other identification documents may prove beneficial. It's advisable to check with your airline about their specific requirements before your trip.