how can we go about this so that he wouldn't get deported

Your fiancé is going about things the wrong way if he wants to avoid being deported. He has only compounded his issues by now violating his probation. Your fiancé can now be sentenced to a term of imprisonment, which significantly increases the risk of being placed in removal proceedings.  In addition, he will not be able to obtain legal status until his criminal issues are resolved. It is not clear what, if any, Perth to residence he has as there is not enough information to make an assessment.  Your fiancé needs to speak to both a criminal and immigration attorney as soon as possible. In the interim, you can read more about family immigration at http://myattorneyusa.com/family-immigration.