Can any of the 12 private banks of federal reserve quit their role?
If I understand the question correctly, they are not private banks. They are part of the Federal Reserve system ie part of the Treasury Department. Where the confusion about being private originates is that the commercial banks that are members of the federal reserve system in the district own stock in the reserve bank of that district and elect 6 of the 9 board members. The bank is organized like a company, but it is not private but public. Of course the fact that there is stock outstanding would in that context make them public and not private. The stock can not be sold by the commercial banks. They do however receive a 6% annual dividend. You might consider the stock as preferred stock in that respect.