My brother and his wife have been married 10-12 yrs they have 3 children 6,10,11. Throughout their lives they have not know stability. Neither parent can hold down jobs, they have been in physical arguments, the kids have seen their father arrested, mom has affairs, they constantly move from apartment to apartment due to evictions. They on occasion have moved in with friends with little bed space. I don't feel either of them are fit parents and want to know if I can get them in a stable environment

So have the mother and father sign over guardianship papers to you, file it in court and have the judge sign it.

If they are not willing to give them over and you can not prove abuse ir other just cause then there is nothing you can do. Many kids are in this situation some get taken off porents many do not because the system says they are being provided for. Instability really has little weight as well as in and out of jail

Contact child protection services and tell them you are willing to foster the children to get them out of that environment.