What's Flipkart's equivalent, and how do I actually report a fake or unauthorised listing there?

Flipkart's equivalent is Brand Assure, once you're onboarded as a trademark owner, it gives you visibility into every seller using your brand name on the platform and a direct channel to flag unauthorised or counterfeit listings, with Flipkart reporting a roughly 1.5-2 day turnaround on resolving IP complaints. You'll need to submit real documentation (your trademark certificate, sample invoices) to back a takedown claim, Flipkart puts the burden of proof on the person reporting, and flagged sellers get a chance to counter with their own invoices, so build your evidence file before you file, not after.