Taxability of revenue sharing jda (joint development agreement)

Respected Sir/Madam,

I Need clarification Regarding Taxability of JDA.

M/s X (Firm -- in Construction Business) and Mr.Y (Company -- in construction Business) entered into a revenue JDA with a M/s.Z (Company) by transferring Land owned by them to Developer for Development, in return X and Y will get share of 10% on ASP each (Actual Sale Price to the Ultimate Customers) Construction is under process....

But as per Section 45, This transaction treated as transfer in the hands of Landowners in the year of transfering the possession to Developer and will be chargeable to capital gains in the same year.

But how to arrive Full value of consideration and cost of acquisition (assuming properties purchased 5 years back, not agricultural lands).

What if the JDA is containing clauses of partly Revenue sharing and partly in constructed property by developer.

Thanks in Advance.