My deceased dad's property is in my sister's name with the agreement that it was still his property so is that still considered hired property

What is your question?

If there is no will then the law cannot recognize shared property in the legal name of another. You do have a right to present your case in a court of law. Without a will, and without her name on the dee,d and not yours, then most states recognize the shared inheritance.

Unless on the deed, it shows some sort of limitation, then the property is hers.
If there is some type of written contract, then it will have to be taken to court to enforce if the sister does not honor it.

If the agreement was just verbal, in most places it will not be enforcable on property