Finally buying in Noida, worried about legal traps

My lease ends in 3 months, and I'm finally taking the plunge for a home in Noida. Been looking at Sector 150, even Gaursons 4th Avenue. Honestly, I'm scared about builder delays and legal issues. How effective is RERA really if a builder like Lotus Parkscape defaults? What clauses in the builder-buyer agreement should I watch out for? Is RERA complaints actually effective?