RERA checks for Gurgaon projects: What to actually look for?

Honestly, I'm fed up of renting in Gurgaon, landlord just hiked rent again. Finally taking the plunge to buy. Looking at properties near Dwarka Expressway, maybe even Paras The Manor. How do you guys *really* check RERA registration for projects? Is just the number enough? Aur builder ka legal track record kaise verify karte hain? Don't want to get stuck with issues later. Any red flags to watch out for in RERA docs?