RERA registration check is more than just a number

My current flat feels super cramped with the kids growing, we really need a 3BHK in Noida Extension, maybe around Sector 150. My wife ki priority hai builder ka track record clean ho, especially with RERA compliance. Supertech Aadri ya VKG Group jaise projects dekh rahe hain, but darr lagta hai koi legal issue na ho. How do you guys actually verify a builder’s RERA registration? Just the number is enough, ya aur kuch check karna padta hai on the RERA portal? Builder delay kare toh kya real legal options hain under RERA? Suna hai bahut log फंसे हैं without proper understanding. Koi solid tips for checking a builder's past projects ka legal status before committing?