Allow me to enlighten you
Ora is indeed Japanese. It's not Latin (I mean, I'm sure they have a word involving Ora or something, but it's not the one used here). Ora is a way in the Japanese Language that tends to bring attention to something. Shouting "ORA!" in Japanese would be like shouting "HEY!" or "LISTEN!" Japanese mothers tend to shout "Ora" at their children to draw attention from them. Alternatively, Goku from Dragon Ball tends to use it to refer to himself. Some may think he's actually using the word "Ore" which sounds similar and is a pronoun for one's self. However, Goku tends to use "Ora" to refer to himself, possibly because he may be using the Kansai accent which would be represented in English as American Southern Accent. Ora can be used as a pronoun or as a way of grabbing attention from someone. I have also heard one translation of it being said to be similar to saying "Take that! And that! And that! And that!". It could also be like punching and shouting "Hey! Hey! Hey! Hey! Hey! Hey! Hey!" not in a greeting fashion, but in the sense of trying to draw your opponent's attention to your strikes or even yourself, like you're trying to assert your dominance as a Mother would over their child when they spank them. It fits Jotaro's personality well, as it is currently in a condescending usage. It's not always condescending, but the way it's being used here is in a condescending tone. I had been told that "Ora" doesn't have a direct English translation, but that it can be represented by other English words or sentences to get the idea across. It's generally a way of drawing attention to yourself, especially in a way that shows superiority or strength.
