What to do if my brother needs counseling but my parents refuse to do anything about it?

Try to get them to: Try to get them to see the potential issues as you observe them. As no aren't wants to believe their child may need intervention. But depending on the age of your brother, the laws of the state you reside, your brother could maybe seek out help without parental consent usually through school counseling or free community help clinics. You can discuss these options with parent or your brother.

Age and desire: If he is over 18 and wishes to seek counseling, he is an adult and is entirely capable of doing so. If he is a minor and or otherwise under age, and your parents do not want him to seek counseling, unfortunately they have that right, As he is a minor in the eyes of the law, they can make that decision for him.