my mother passed away and my brothers are very evasive about her will. How can I obtain a copy?
If the will goes to probate it is filed with the court and you can see it.
I'm assuming your father predeceased your mother. You and your siblings are entitled to equal shares of her estate by law.
If no will is found, either you or one of your brothers will have to make application to the Surrogate's Court in the county where your mother resided for Letters of Administration.
You should note that any assets held in joint ownership or with a designated beneficiary pass to the survivor and are not part of the estate.