"Ideally we'd have preferred Ivanka", he said, referring to the president's eldest daughter, who is now an adviser to her father. "I just thought he was president".
A full page advertisement that ran on the cover of several Indian newspapers over the weekend featured a picture of Trump Jr., alongside the tagline "Trump is here".
Early buyers of apartments at the Trump Towers in Gurgaon were last month offered the chance to dine with Trump Jr.in NY.
The younger Trump said his itinerary did not include interactions with government officials in an intentional effort to steer clear of politics.
Trump Jr's visit to India comes after his sister, Ivanka, visited Hyderabad in November a year ago to attend the Global Entrepreneurship Summit (GES).
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Air strikes have left about 250 civilians dead, with retaliatory rocket fire on Damascus killing about 20, the monitor said. But rebels have denied the claim, with top Jaish al-Islam figure Mohammad Alloush telling AFP there were no negotiations.
The rest of the details of Donald Trump Jr.'s itinerary are hazy despite repeated emails to the Trump Organization and its Indian partner Tribeca. In addition to an oversupply, demonetisation has hurt sales at competing developments, but the Trump name remains a draw. Tribeca Developers and RDB Group did not respond to requests for comment.
Trump Jr. also plans to spend part of the trip meeting with investors and business leaders, as well as attending an advertised $38,000-per-ticket "conversation and dinner" event with Trump Tower Delhi National Capital Region buyers, according to the Post.
The Trump Organization has five projects in India, including an office building development in Gurgaon, making the country the brand's biggest market outside the United States.
Critics have often complained of the high cost of Secret Service agents accompanying the Trump children on private business trips, straining the agency's budget. "This will open up the country to outside markets", Trump said.
The election changed that, he said, meaning the kids now have to step in.
"I have always had a deep admiration for your country and for its people, and a profound appreciation for your rich culture, heritage and traditions", Trump said in June during a state visit by Modi, one of many such words of praise for India he has offered in the a year ago.