My mom got deported about 6 years ago while trying to become legal. What can I do to bring her back?

You should not give up your efforts to bring your mom to the US. She has three sons here. Her husband is here. You should prepare good papers and apply either for a humanitarian relief, or waivers, or hardships, or else... It all also will depend under what Section your mom was deported and whether she had a criminal history (if any, besides violations for overstay!?) 20 year ago or before being deported.

If you have spoken to a number of experienced immigration attorney and they all agree that there is not hope, then I would probably have to agree with them, since you probably told them more about your mother's situation than you listed here.

I believe your mother's case is sufficiently serious for you to actually go and consult with a very experienced immigration lawyer.Based on information provided, it seems that your mother has been deported twice from the US, the first, about 20 years ago, followed by another one 6 years ago. If this is so, her recent deportation was under s.241(a)(5) INA Reinstatement of Order of Removal. An alien who has been deported on two or more separate occasions is considered an "immigration recidivist" They are generally not eligible to get green card until they have stayed outside the US for 20 years, starting from the date of the last deportation. If her second deportation was 6 years, ago, I am afraid, she may have to remain outside for another 14 years. Under the circumstances, she must not attempt to come to the US again illegally or else, the 20 year clock starts running again. It is also important to identify the particular immigration law she violated 20 years ago that resulted in her first deportation order. In light of this, I strongly believe, you will need a full and detailed consultation with an attorney to advise you of all your options. Meanwhile, and until this matter is resolved, it is futile and very dangerous for her to attempt future illegal entries into the US without DHS permission.

Probably not. Until she has satisfied the conditions of her deportation order, she will not be permitted to enter the US.

It may still be possible for you to help your mother, but more information is needed. What are the exact dates that your mother has ever entered and left the United States from her very first entry?