RERA: What happens when builders actually delay

RERA is supposed to protect us, but the ground reality in Bangalore feels different. I'm looking at properties, maybe near Sarjapur Road, even VDB projects. My parents keep saying verify everything. But yaar, builder ka track record kaise check karein properly? Especially for OC delays ya agar Sobha Royal Pavilion jaisa project late ho toh kya options hain? RERA complaints sach mein help karti hain ya bas formality hai?