Between the events in The Incredible Hulk (2008) and The Avengers how did Bruce Banner end up in India when he was last in Canada? Did it have anything to do with what happened at the end of the Incredible Hulk movie?
In a way it did. The ending of The Incredible Hulk we see Bruce attempting to control the transformation, a few years later in The Avengers we see that he has succeeded in gaining some control over the Hulk. We can then assume that his trip to India was probably part of that training process. When Bruce meets Natasha for the first time this conversation between them occurs which may shed light on the subject:
And a bit later in the same conversation:
A large part of Bruce Banner's self control is based on distracting himself and thus mentally distancing himself from being The Hulk.
Now how does he do that?
Banner being a world class physicist employs his immense knowledge ( He is described by Marvel comics as "possessing a mind so brilliant it cannot be measured on any known intelligence test."1) in humanitarian efforts. He thus lands up in Calcutta(India) where he is just another foreigner, far far away from the United States and is practically unrecognizable.
Here he immerses himself in fighting the endemic spread across the city and his work becomes his savior. It is safe to assume that Bruce Banner keeps traveling (and quite frequently) to far-flung places where he can be a contributing member of the society through his work and keep himself distracted enough to not turn into that "Green-Rage-Monster".