CA Site Relinquishment

A builder/Layout developer had obtained a sanction plan to form a layout by showing CA sites in the proposed and approved plan in year 1992. The Layout developer got the approval on the basis of POA signed by various farmers for their respective land survey numbers. Later the builder never got the titles transferred by the way of sale deed for the CA sites, nor any consideration was given to them. He also did not relinquish the land to BDA. As the title remained with the farmers they later (after 20 years in 2012) sold the land to private parties by proper sale deed and registration. Now the Layout association put a PIL against the BDA and the builders stating the CA was not given to them. High Court of Karnataka disposed the case with guidance to BDA to check and clear the CA sites if there was any encroachment. But since there was no registered sale deed done by the land developers, and no relinquishment done , all documents were with the farmers. They have clear title deeds , Encumbarances show no reflection of change of ownership or any transaction. Also BBMP has given approvals for construction to the people who have purchased the lands from farmers. Banks have also given loans.Now my question is whether the approved plans stand valid in lieu of no reliquishment done by builder/layout developers. What is the plight of the people who have purchased the land from the farmers which was DC converted and all sale deed registrations done correctly.