My brother likes dancing, but his parents don't agree. As a brother, how should I handle this matter?

What you like should not be eaten as food. I think I should support my brother to dance, but it can't affect my studies. Communicate with him well, let him study hard at school, in exchange, you support him to dance, let him not associate with bad people, and finally send him to a formal dance studio. Although college students are not very mature psychologically, just like children, so don't use too intense tone, just tell him his thoughts like making friends, and then you can say your thoughts. I'm sure he will understand.