As far as we know, the government and society of Oceania does conform to these definitions pretty well.
The government is probably an oligarchy. We do know that the Inner Party controls the major decisions made by the government (although we are not really clear as to what role Big Brother plays, if he exists). It maybe, however, a bit iffy to call 6 million people an oligarchy.
As far as collectivism goes, it is not completely clear to me. This is mainly because pretty much no one has anything that they can own -- there's not much wealth. However, we do know that the government runs pretty much everything, so there is probably little serious private property.