Had cerebral contusion during fall. Neurosurgeon says it is 6 millimeters. How will that affect me?

Cerebral contusion. Symptoms will depend on what part of the brain is involved, . If you are not experiencing any symptoms by now, it is possible you will not experience any defecits in the future.
Depends . I presumed ct scans done.Brain contusion can impair wide range of brain function depends on size and location. Large contusions may cause brain edema and increased intracranial pressure. It may enlarge in the hours or days following initial injury and may cause neurologic deterioration. You mentioned 6 mm, most probably punctate hemorrhages, localized without symptoms.Follow up your neurosurgeon.