So if we reach canada after 3rd of feb we have to quarantine in hotel? Or the date is not decided yet?
Not known at the moment. But yes, after 3rd Feb you'd have to land on one of those 4 airports.
Official advisory:
As soon as possible in the coming weeks, all air travelers arriving in Canada, with very limited exceptions, must reserve a room in a Government of Canada-approved hotel for three nights at their own cost, and take a COVID-19 molecular test on arrival at their own cost. More details will be available in the coming days.