Do you mean a register that can be searched? I haven’t heard of that, outside of doing a records search as part of a police check. You can have an intervention order made in one state recognised and enforced in another state. That is sometimes referred to as being registered.
This case is so horrifically sad. Interestingly that there were such public criticisms of the independent children’s lawyer and whether that will have any long term implications for ICLs, and therefore court outcomes, in the future.