I expect there will be no issues BUT the carriers do give students hard time in transit. If you have an option to fly non-stop from Delhi to Toronto, I'll strongly suggest that route. I am a citizen of Canada and I recently accompanied an international student from Pakistan via Emirates (Dubai). The documents were thoroughly checked in Lahore by Emirates and were allowed to board after getting authorization BUT at the gates for the flight to Toronto at Dubai Airport, I've seen that they questioned every student and asked them to sit on the side and wait for further instruction after they verify everything and ask Canadian authorities if this xyz student is allowed to board. Emirates off-loaded at least two students from the same flight and clearly every student was panicked/nervous with the situation. Though, it wasn't that difficult for the accompanied student with me since one of many reasons could be that I was accompanying the student and/or classes are yet to start and were not already taking classes online or the pre-authorization at Lahore airport from Emirates. Who knows at this point.
What I learnt from this experience is, it's better to fly non-stop if you have an option from your country to Canada instead of taking a stop-over since that can get ugly.