You can start with following primary topics:
1. Pre Partition
a. Entrance of East India Company
b. Causes of Demise of Mughal Empire
c. Reformist Personalities i.e, (Sirhindi, Shah Waliullah, Shaheed Barelvi etc etc)
d. Reformist Institutions i.e, (Aligarh, Deoband etc etc)
e. Events after Congress Creation till birth of Pakistan

2. Post Partition
a. Constitutional Crises
b. Democracy
c. Debacle of East Pakistan
d. Political Development
e. Provincial Autonomy
f. Water Crises
g. Energy Crises

These all will at-least makeup your mind towards Indo Pak History Paper II, as far as paper questions are concern, questions are analytic in nature.
Rest depend on your writing skills.

Thanks