Monkey chants were heard from sections of the away support in the 0-0 draw.
Villas-Boas said he did not hear the chants, but the Portuguese believes European football’s governing body will respond if necessary.
“Uefa is very active on this kind of situation,” he said.
“And our overall objective is to kick racism out of football.
“I can’t point the finger at anyone in any way shape or form because I didn’t hear anything. It’s for the authorities to follow up in any kind of investigation.”
Uefa president Michel Platini was at White Hart Lane, where Defoe’s fellow England international Aaron Lennon and second-half substitute Andros Townsend were also reportedly subject to racist abuse.
Uefa said it was waiting for the match report before making any decision on potential disciplinary proceedings.