My dilemma: ready vs. under-construction for peace of mind

Honestly, I thought finding a smaller flat after kids moved out would be easy. But Gurgaon mein it's so confusing! I'm looking at Ansal Valley View Estate, jo ready hai, versus Adani Samsara Ivana, which is still under-construction. Ready-to-move mein society aur RWA ka idea lag jaata hai, plus immediate possession mil jaati hai. But under-construction mein kya risk hai, especially for an older couple? Maintenance charges ka bhi darr hai, for a settled life. Adani ki maintenance kaisi hogi? Any thoughts on which is better for a family looking for low-hassle living?