Is communism a type of oligarchy?

Don't listen to that person other person they don't know what they're talking about. Technically, communism is a type of monarchy and to be specific an absolute monarchy. However monarchy/Dictatorship never truly exists because it's always a group with one person as the visible leader. Oligarchy means "ruled by a few" and monarchy is just a different type oligarchy.

So there are two answers to your question

1. Technically, no it's a monarchy.

2. Figuratively, it's an oligarchy but not a true oligarchy.