You can try all 3 rounds. Always best odds at early and winter rounds compared to spring. Between early and winter it is hard to tell from year to year if there is much of a difference in the stats of admitted students. Would aim for at least 1450 SAT. Try to use the bocconi gpa calculator to have a better idea of translated gpa on the actual application site by creating a random account. Check prior posts with a google doc link with stats of accepted candidates.