Valuation of land for GST in real estate project

As per Entry No. 49 of List-II of Seventh Schedule 'Taxes on Land and Buildings' is a State subject. Therefore, Sales of Land is subject to State Stamp Duty. Constitution grants concurrent powers to Union & State to levy GST, subject to recommendations by GST Council.

source https://www.caclubindia.com/articles/valuation-land-gst-real-estate-project-45187.asp