Investing in Delhi: Trusting RERA or deeper checks?

Spent the whole Sunday checking out options in Dwarka and Vasant Kunj, including Arya Group's Home Making Smart Floors. Builder ka track record kaise check karte hain properly? I'm looking at a 3BHK around ₹2Cr, and legal clarity is my main concern. RERA registration numbers bas website pe dekhna enough hai kya, or are there deeper checks? Title verification steps kya hain jo log usually miss kar dete hain? Investors, please share your experience. Kya RERA complaints actually effective hain, ya sirf paperwork hai?