First, please don't start multiple threads for the same question. If you need to add to a prior question, use the Answer options to add another post.
If there is no will then he must have transferred the property to the 3 siblings prior to his having passed. If that is the case, then the property was no longer a part of his estate and is owned by the 3 siblings. If you are not one of the 3, then you have no interest in the property. If the property title is not in the 3 siblings names or was not at the time of his death, Then they have to follow the laws of inheritance for your area. So you need to check the deed and find out when it was recorded.
If you feel that the 3 coerced your father into giving them the property before his death, you can try to overturn the transfer, but that's going to cost you in legal fees.