The powers of the Commissioner are restricted to the terms of reference which are established by the Government prior to commencement.
The terms of reference can be found here
http://www.childabuseroyalcommission.gov.au/about-us/terms-of-reference
This is part of those terms and basically states that they have been given the power to make enquiries and recommendations. Any legislative changes must then come from the Government.
to inquire into institutional responses to allegations and incidents of child sexual abuse and related matters, and in particular, without limiting the scope of your inquiry, the following matters:
a. what institutions and governments should do to better protect children against child sexual abuse and related matters in institutional contexts in the future;
b. what institutions and governments should do to achieve best practice in encouraging the reporting of, and responding to reports or information about, allegations, incidents or risks of child sexual abuse and related matters in institutional contexts;
c. what should be done to eliminate or reduce impediments that currently exist for responding appropriately to child sexual abuse and related matters in institutional contexts, including addressing failures in, and impediments to, reporting, investigating and responding to allegations and incidents of abuse;
d. what institutions and governments should do to address, or alleviate the impact of, past and future child sexual abuse and related matters in institutional contexts, including, in particular, in ensuring justice for victims through the provision of redress by institutions, processes for referral for investigation and prosecution and support services.
AND We direct you to make any recommendations arising out of your inquiry that you consider appropriate, including recommendations about any policy, legislative, administrative or structural reforms.