Maybe. Look up the rules for who can be claimed as a dependent. You need to know the parent's income and how much they pay for their support vs how much client pays, etc.

Yes, I know! but groceries' Sofware do not give any option where to entering this parent claimed as dependent. If, he could be on the same ranging line as children are?  

I don't use ProSeries, but aren't all dependents entered in the same place?

All dependents are listed in the same area. 

If that dependent person has no blood or marriage relationship to the taxpayer you'd choose NONE as the Relationship in the drop down menu.