This is not specified on the Investor Visa for Italy Policy Guidance: Family reunification is allowed and regulated by the general laws on the subject, in particular by art. 29 of Legislative Decree no. 286 of 25 July 1998 (Consolidated Act on Immigration – TUI).
The categories of family members for whom reunification is allowed are listed in art. 29 of the TUI:
a. spouses not legally separated and aged over 18;
b. minor children – including those of the spouse, or those born out of wedlock – who are unmarried, provided that the other parent has given his or her consent;
c. dependent children aged over 18, if for objective reasons they are unable to provide for their essential needs due to health conditions implying total disability;
d. dependent parents, if they do not have any other children in the country of origin, or parents over 65 years of age, if the other children are unable to support them due to serious and duly documented health conditions.