Upvote:5
If you enter Canada to visit, there is no difference between "a few hours" and "a few months". You would need to get the same permission in either case.
It's unclear from your question whether you are a permanent resident in the US, and this makes a difference for entry into Canada. US permanent residents can enter Canada for a visit without any additional documentation (just passport plus US permanent resident visa or green card). However, if you are not a US permanent resident, then as an Indian passport holder you will need a visitor visa for Canada.