Capital gain - query

Student (.) (76 Points)

27 August 2019  

A building was constructed on open Plot under Joint Development Agreement in 2006. Both builder & landlord took 50% share of saleable area after recovering cost of construction.

Now, in 2019, the landlord has sold 1(one) flat for 60 lacs.

What will be the Cost of Acquisition for calculation of Long Term Capital Gains??