Kindergarten for Kid of 2&half (Montréal)

Dear All,
My boy and me will move to Montreal in about May/June this year, by then he is about 2 and half, just wonder if private Kindergarten is the only option or we can get public one? in both cases, what will be the rough annual budget for it?

in general, how many hours a kid will stay in kindergarten per day?
(btw, we are not citizen or PR, only temp visitor)

Thanks, Merci Beaucoup!
Tony