RERA checks: What buyers often miss before signing

Since last Diwali, we've been hunting for a 3BHK in Pune for the kids' school admission. Majestique Mrugavarsha Phase III looks promising, but honestly, I'm stressed about legal stuff. How do you actually verify a builder's (like Vypak Properties) track record? What RERA red flags should I watch for, especially regarding delayed OCs? Is RERA truly effective?