Section 5(2)(d) in The Bombay City (Inami and Special Tenures) Abolition Rules, 1972
(d)in the case of a lease of a plot with superstructure without payment of premium, where annual rack rent is reserved, the difference between the amount of 16 times the annual rent so reserved and the value of the superstructure on the date of the lease, shall be the estimated price of the plot as an unbuilt plot;