A fair question. Sanctioning individuals would theoretically be possible. Someone who knows more about this can chime in as to the pros and cons (unlikely such a person lurks on HN), but I think there may be what might be termed an asymmetry here where many (maybe most?) of the responses that would make the Indian government feel punished would be things that would hurt Canada as well (e.g. sanctions).
As the other poster said, Canada could also do some tit-for-tat shady shit. Maybe Trudeau's dad would have been willing to do that, who knows.