en_tn/rom/04/11.md

a seal of the righteousness of the faith that he had already possessed when he was in uncircumcision

Here "righteousness of the faith" means that God considered him to be righteous. AT: "a visible sign that God considered him righteous because he had believed in God before he was circumcised" (See: rc://en/ta/man/translate/figs-explicit)

even if they are in uncircumcision

"even if they are not circumcised"

This means that righteousness will be counted for them

You can translate this in an active form. AT: "This means that God will consider them righteous" (See: rc://en/ta/man/translate/figs-activepassive)