Can I file a cyber crime complaint if I don't know who committed the fraud?

Yes, absolutely — you don't need to know the identity of the person who defrauded you to file a cyber crime complaint. You can file it through the national cyber crime reporting portal or at your local police station's cyber cell, providing whatever details you do have, like the phone number, bank account, transaction IDs, and any messages or communications related to the fraud.

Investigators have access to tools and processes — tracing bank accounts, phone numbers, and IP addresses — specifically designed to identify perpetrators even when the victim only has limited initial information, so what might seem like very little to you can still be a useful starting point for investigation.

For financial fraud specifically, reporting quickly (ideally within a few hours) significantly improves the chances of the transferred money being frozen or recovered before it's moved further, so time is genuinely important here. File your complaint as soon as possible, and keep all screenshots, messages, and transaction records you have as supporting evidence.