How do we know that there are computers in AD (Domain) hosting the configuration manager console ? Are we going to first make a collection of all such computer in AD and then configure "Active Directory System Discovery" ?

AD Discovery has nothing to do with software installed on those computers. AD system discovery is able to discover computer accounts in AD. Hardware inventory does provide information about software installed on each computer that got the ConfigMgr client installed. So you can use "add/remove programs" related reports to find out where the ConfigMgr console is installed.Torsten Meringer | http://www.mssccmfaq.de

Thanks !! Regards Raman Katoch