EMI vs Rent is driving me crazy in Noida

Sector 137 mein rent de deke toh tang aa gaya hu. Landlord ne phir rent badha diya. Finally taking the plunge. I'm looking at AVJ Group projects, but under-construction hai. Darr lagta hai RERA stories sunke. Should I just buy ready-to-move even if it's smaller? EMI vs rent math doesn't seem to add up kabhi kabhi. Is it worth it in Noida to buy instead of rent, seriously? Advice please!