GST on Shops - Goods and Services Tax - GST

If someone unregistered in GST purchases land and after demarking as 80 commercial shops, sales 45 shops without construction as land for shop and 35 shops after built up. Each shop is valued more than 75 lacs. Being commercial shops, is he liable to registered in GST? Is sale value of unconstructed/ not built up shops also to be considered for valuation gst liability or only of constructed shops ? Here completion certificate is not being provided by any authority. Which any other documents can be treated as completion certificate ?