The Tandons' Motivations
Without much known about the Tandons, it is difficult to surmise what their exact motivations were in donating such a large sum to the order of New York University. Neither Chandrika nor Ranjan had any ties to the school until after the renaming, where they were named board members of Stern and Tandon respectfully (Engineering Transformed, NYU Tandon). Chandrika and Lita had attended Yale, Ranjan had attended Harvard - so why NYU? The closest family relation to the school comes from Chandrika's sister, former PepsiCo. chairman and CEO Indra Krishnamurthy Nooyi, who had received an honorary doctorate from the school on May 14th, 2008 (Indra Krishnamurthy Nooyi Receives Honorary Doctorate From NYU, NYU), and the Tandons relative living proximity to NYU considering that they've self declared themselves to live near Washington Square Park in New York City.
However, a possibility is that the Tandons had the desire to donate to a prestigious school in state, where they could deduct the donation on their taxes. Although their exact net worth remains a mystery as a result of their private status, a conservative estimation can be taken from the assets value of Ranjan's hedge fund - Libra Associates LLC. According to Wallmine.com, Libra Advisors LLC have assets of over $2.5 billion as of March 1st, 2024.
Such an income would invoke a large payment of taxes - for New York state taxes alone, they would pay 8.82% of their income if filing as a jointly married couple in 2015 (State Individual Income Tax Rates and Brackets, Tax Foundation). However, New York State allows only up to 50% of this tax payment to be given to charity instead of the government (How to Receive a Charitable Tax Deduction, Fidelity Charitable). Taking Libra Associates LLC's value to generate an estimate (Wallmine.com), 8.82% of $2.5 billion would be as much $220.5 million, and 50% of that is $110.25 million - which would be more than enough to make the $100 million dollar donation to NYU entirely tax-free.
Moreover, one might question why another prestigious school in New York, such as Columbia University, was not chosen to be the recipient. There is a possibility that since NYU Poly was struggling with the $90 million in debt (POLY ARCHIVES & Special Collections, Poly-NYU Merger), their barrier for naming recognition for their donors would be lower than that of a school generally with a larger endowment like Columbia University. Having name recognition for their donation could have been considered a sizeable boon for the Tandons, who have participated in much philanthropic work.
Another possibility is that NYU gave the Tandons more of a guarantee and the flexibility as to decide what their donation would be used for. However, neither of these possibilities is confirmable without an explicit explanation of their decision-making by the Tandons, which does not appear to be information public to the researchers. With so much information remaining private about them, the Tandons continue to maintain their air of mystery - even as they make news for doing things that few in the world can claim to have done.