Noida investment: Sector 51 vs. Earthcon Universal?

Guys, I'm based in Dubai and looking to invest in Noida. Can't visit easily, so need your help. What do you think about Sector 51 for rental yield? Is it worth buying ready-to-move or under-construction? Has anyone experienced Earthcon Universal Infratech Pvt Ltd? Builder ka track record kya hai? Mujhe advice chahiye, I'll need a property manager later. Is it sahi to invest now or wait? What's your take?