One of my friends studied at Banaras Hindu University (BHU). According to him, BA social science entrance exam demands you to be knowledgeable in the field of humanities. 

All you have to do is cover the current affairs section very well and along with that keep an eye on the previous year's questions. Some questions include topics on psychology or philosophy. For this, you don't have to go through the topics elaborately. You can solve previous year's questions to get a general idea. These are a must to pass BHU BA Social Science entrance examination. 

For current affairs, you can keep yourself updated by reading newspapers and magazines. This will improve your vocabulary and writing ability. Knowing history will also be helpful. So prepare accordingly.