@pravin_speaks  I would again strongly recommend you closely read the announcement I linked to above, Transition to private repositories for CDH, HDP and HDF because it has a section labeled Installing/upgrading Ambari & HDP via Cloudera’s private repository that in turn has links to extensive documentation on how to download and install certain earlier versions of Ambari and HDP; to be specific: Ambari 2.6.x.x and HDP 2.6.5.0 Ambari 2.7.x.x and HDP 3.x.x.x …as far as whether or not earlier "versions of Ambari and HDP can be downloaded if valid access is received from cloudera", that question is addressed in that same announcement, which states:   …new patch releases of …Ambari have been made available and are required to access Cloudera’s private repositories, which now contain these new and existing releases. Versions other than those outlined below will no longer be able to install CDH, HDP or HDF from Cloudera’s public repositories. Emphasis added.      ... View more