Generally, derivative beneficiaries for the EB-5 program are limited to spouses and children under 21 years of age. Once you obtain permanent residency, you can petition for parents.
As an Australian EB-5 attorney we can assist with guiding you through the EB-5 process and hence please contact us for help. You cannot include your parents in your EB-5 process. There may be alternative processes for your parents to visit the U.S.