What special subject should I take in B.A? I want to do MBA in HR after my B.A.

Better go for BA psychology, psychology can help you a lot in MBA HR. All the best

Undoubtedly Bachelor's in Sociology or Psychology!

do social work(bsw) or Sociology and public administration

Hello dear, there is no special connection between arts and management. Domain are different. U can go for any subject however PSYCHOLOGY may help you in future as a HR if u opt it in grad. All the best. Thank you.