SANscreen was rebranded as OnCommand Insight with version 6.2.0. The current shipping maintenance release of OCI is 6.3.2. Nearly any version of SANscreen can be upgraded to OCI 6.3.2.
As mentioned by ostiguy, OCI is just a new name of SANscreen. You can upgrade from any version to latest version, make sure you follow the right procedure. I, myself have done it many times in production environment.