KSC Open API
Kaspersky Security Center API description
HostGroup::UpdateGroup ( int  nGroup,
params  pInfo 
)

Changes attributes of the existing administration group.

Parameters:
nGroup(int) group ID.
pInfo(params) container with the group attributes. May contain non-read-only attributes from the List of group attributes.

See also how to use the KlAkOAPI Python package:

            server = KlAkOAPI.AdmServer.KlAkAdmServer.Create("https://ksc.example.com:13299", "username", "password", verify = False)
            oHostGroup = KlAkOAPI.HostGroup.KlAkHostGroup(server)
            strNewGroupName = "TestGroup new name"
            # retrieve the full group name
            oGroupInfo = oHostGroup.GetGroupInfoEx(nGroupId, ['grp_full_name']).RetVal()
            print('Group', oGroupInfo['grp_full_name'], 'is to be renamed into', strNewGroupName)
            # update the group name
            oHostGroup.UpdateGroup(nGroupId, {"name": strNewGroupName})