Step 1: Understand the operation's goal.
Delhi Police's Anti-Human Trafficking Unit (AHTU) conducted a special drive in the southwest district to trace missing persons and reunite them with their families.
Step 2: Recall the operation's name.
The operation is called "Operation Milap," where Milap means reunion in Hindi. It successfully traced 1,303 missing persons in the southwest district during 2025.
Step 3: Eliminate the distractors.
Operation Milan, Suraksha, and Raksha refer to other unrelated operations. "Milap" (reunion) is semantically the most fitting name for a missing-persons tracing drive, making it easy to remember.
\[ \boxed{\text{Operation Milap}} \]