You should speak to an attorney to discuss the specifics. He will need to know whether your mother had a will, whether that will was probated, and whether a probate proceeding was ever commenced and/or concluded.
Were there any estate proceedings? Your only recourse here is to attempt to re-open them. If they never happened, then time may have ran out at this point, however speak with an estates attorney at length to be sure.
You need to consult with a probate attorney as of yesterday as your time may have already run out.
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