New Delhi, Nov. 13 -- "Lawyer, 63, gym rat."

That's how Anil Pradhan introduces himself to 19 other singles at a dating mixer for over-50s on the rooftop of a Delhi resto-bar. It's a warm September evening, but Pradhan, who arrived from his hometown of Shimla just 2 hours ago, refuses to take off his weathered leather jacket-he calls it his "lucky charm"-paired with blue jeans, black shirt, and brown Derby shoes. His salt-and-pepper hair is slicked back and he has spritzed on an extra-strong oud-vanilla cologne.

That Friday marked Pradhan's first attempt at dating. After his wife died of cancer in 2020, Pradhan had buried himself in work and exercise. Their union, arranged by parents, had lasted 40 years.

Like the other 19 participants...