Noida property: The hidden costs nobody warns you about

Has anyone actually managed to get the advertised rental yields in Noida? I'm based in Dubai and thinking of investing, but can't do a site inspection myself. I'm looking at 2BHK flats in Sector 51, maybe something by Parsvnath Developers. But honestly not sure if the rental income will cover the EMI. Seen some properties that look good online, but worried about possession delays – heard so many horror stories! Need a property manager too, which will eat into the profits. Is it worth buying under construction to save money, or should I just go for ready-to-move? Also, how much extra should I budget for hidden costs like stamp duty and registration? Koi idea hai?