As you are from Public Administration, Civil Servant can be a great opportunity for you so that you can apply your skill and knowledge in the field. So preparing for UPSC or State Civil Service can be a great option for you. Now if you don't want to go for it then you can go for LLB. Being a lawyer you can do social justice to the Administration. Apart from this obviously you can go for MA and followed by PhD to be a professor of Public Administration.

These are some of the lucrative career choices after BA Public Administration. If you want you can join NGO's and other to help them in Public Administrative procedures.

I hope my answer helps. All the very best for your future endeavors!