Can I add my child's name in my interview schedule after he gets the passport?

[desperatehusband]

I'm coming to India during March and me and wife are going to get our H1 and H4 visa stamped. I'm working now to get my passport done (through affidavits). Considering the situation,its better to book interview dates earlier.
Is it possible to add my son's DS160 after we got his passport so that he can attend the visa interview alongwith us so as to avoid the long journey from my hometown to consulate twice?

too bad, they have discontinued the dropbox ...even for kids...