did i use the comma rule correctly?

The oil from Eucalyptus trees which are native, to Australia is known for its medicinal properties.

Nope, try

The oil from Eucalyptus trees, which are native to Australia, is known for its medicinal properties.

The oil is known for its properties.

"which are native to Australia" describes the trees, but is not necessary to convey any meaning about the oil.

Now, if there are trees under discussion which are not native to Australia, then the first comma needs to be deleted, since the only trees of interest are those not native to Australia. Just as if you say

The boy who is tall has red hair.

That implies that there are other boys who are not tall.

however,

The boy, who is tall, has red hair.

means that the boy has red hair, but by the way, he is also tall. Nice to know, but not necessary.

No, you did not use the comma rule correctly in your sentence. The placement of the comma is incorrect. Here's how you can fix it:

"The oil from Eucalyptus trees, which are native to Australia, is known for its medicinal properties."

Explanation:
In this sentence, you are providing additional information about Eucalyptus trees being native to Australia. This information is called a nonrestrictive or nonessential clause, which can be separated from the main sentence using commas.

Here's the breakdown of the correct usage:
- The oil from Eucalyptus trees is the main subject of the sentence.
- The nonessential clause "which are native to Australia" provides additional information but is not necessary for understanding the main point of the sentence.
- Commas are used both before and after the nonessential clause, setting it apart from the rest of the sentence.

Remember, when using nonrestrictive clauses, it's important to separate them with commas to make the sentence clearer and easier to understand.