Builder's RERA status: Just a formality?

Just got possession of my Infinitum Infratech flat in Jay Hind Apartment last month, and honestly, a lot of legal questions are still bugging me. RERA registration ka verification kaise karte hain, I mean, beyond just seeing it on a website? Kya kisi ko pata hai kaise builder ka legal track record check karein, especially for past delays or issues? And RERA complaints, are they actually effective, ya bas paper pe hain? I'm worried about future issues. Any advice?