Solution

We use "at" when referring to a specific point or location—and "the campus" in this sentence is considered a specific place.

Let’s break it down:

• "at" = specific location
  ➤ "He's waiting at the bus stop."
  ➤ "She's studying at the library."
  ➤ "We're meeting at the restaurant."

• "on" = surface
  ➤ "The book is on the table."

• "in" = inside an enclosed space
  ➤ "He's in the building."
  ➤ (You might say "in the campus" if you’re thinking about being within the grounds of a large university, but "at the campus" is more natural when referring to meeting someone there.)

So: ✅ "Jagdish is waiting for me at the campus."
is correct because it's talking about a meeting point or location.