I have options like PGD in Canada, M.Sc in Australia, M.Sc in Ireland and M.Sc in New Zealand. Which is the best place for jobs and PR?

I am not sure about Ireland and New Zealand but Canada and Australia would be your better options for PR. Recently, PR entry requirements changed in Canada though you can opt PGD from any Canadian business school. Ref: https://www.quora.com/Is-it-worth-of-doing-post-graduation-diploma-from-Canada-c

Hi, These countries have very good post study work options for international students. Canada is a go-to destination now so you CA explore it. Australia is competitive and expensive, also requires 2 academic years course to be eligible to apply for work permit. A tip is to check the labour shortag