Upvote:2
So now the last name for my dad is different in his passport and my passport.
This was not a problem when I was applying, I doubt it has changed since then.
There are plenty of colorful family name combinations. For example, in my family I am the only one that has my father's first name as my last name - all my siblings have my father's last name as their last name.
No problems getting B1/B2/F1 visas for my family members.