Noida Extension property: RERA and legal checks?

Okay, I'll be honest — buying for myself in Noida Extension is different even for me. I'm checking a Kkay project, Paradise Green Plaza. RERA registration toh dekha, but kya bas itna enough hai? Title verification mein kya red flags dekhne chahiye? And RERA complaints, are they actually effective, ya bas paper pe hai?