When no return has been filed, or a return has been filed within two years of the bankruptcy, the taxes cannot be discharged in Chapter 7.  However, they can be discharged in Chapter 13 if the tax return was due more than three years before the commencement of the bankruptcy case and was not assessed within 240 days of the filing.

You will usually need to prepare and file the returns for the priority tax years, either before the bankruptcy filing or shortly thereafter.  You should consult with an attorney before you file any unfiled tax returns to determine the most advantageous time to file the returns.

It may be possible to negotiate other settlements with the IRS.  Consult with an attorney before you decide how to deal with your taxes in bankruptcy.