Can we delete the wom-default-clientssl and serverssl profiles ?

Profiles in profile_base.conf are not used at run-time. They are only used to create the initial default BIG-IP configuration such as the first time you start up your BIG-IP system or on a "tmsh load sys config default." Only the ones in bigip.conf apply at run-time. Removing a default profile from bigip.conf may cause the issues jaikumar identified earlier and is not a recommended practice due to the dependencies jaikumar also identified. Instead of asking the question, "Why not remove them..." I would ask you why you do want to remove them? Are you having trouble with resource allocation or looking to make the running config smaller?