IF it has been filed with the courts you can get a copy there, but normally its not filed with the courts until someone opens probate. Otherwise, you would have to get a copy from the executor/administrator of the estate.
The question is who is handling the estate. If the estate is small (I think the Tennessee limit is $25,000), it may be informally handled by the small estate process. If it is larger, a full up probate will be conducted. If someone has started either of these processes, you would contact them. If not, you can possibly start one. An attorney will help. The first step of either process is to determine if there was a will or not and find it. If your mother had an attorney to draft it, that's usually a good person to enlist in the process. Otherwise, you may need to dig through her personal papers.
By following the suggestions of the other responses. And if you cannot find a will you can open probate under intestacy and ask to be appointed representative of the estate. If you are sole heir you get everything after debts and expenses are paid. If you are not the sole heir you share in accordance with the rules of intestate succession.