Rental yield claims from builders are mostly fake — fight me

I work in real estate but buying for myself is different, right? I'm looking at Noida as an investment. Everyone hypes rental yields, especially for 2BHKs. But honestly, I'm skeptical. Builders like Bamatech Builder quote crazy numbers. I checked Sector 126 and the actual rent seems way lower. Is anyone actually getting the advertised 5-6% ROI? Or is it all super area vs carpet area games and inflated prices? I'm thinking under-construction might be better for appreciation, but then there's the possession-delay risk. Should I just stick to ready-to-move even with lower yields? Kitna safe hai Noida mein, realistically? Anyone with experience, please share! I need real numbers, not builder BS.