The term the old man is used three times in the New Testament (Rom. 6:6; Eph. 4:22; and Col. 3:9). In Romans 6:6 the old man is something personal, whereas in Ephesians and Colossians, according to the context, it is clearly something corporate.
When we are saved and baptized, we put off the old man both in a personal way and in a corporate way.
In Romans 6:6 the old man refers to our natural but fallen life; it is the life of our soul, which acts independently of God. This is the “I” that Paul said was crucified with Christ (Gal. 2:20). Since that old “I,” the old man, was crucified with Christ, it is good for nothing but burial, which Paul speaks of in Romans 6:4. Thus, in this sense the old man is something personal.