Hello Aspirant,
Most of the entrance questions are taken from the syllabus of BHU BA political science. The questions will be related to Political theory, India government and politics, Indian national movements, political thoughts, international relations, public administration and Political sociology etc. To understand the pattern and to get a better idea solve previous years question papers.

Overall be good with your UG syllabus and be thorough at recent political theories and their fathers, along with the constitution of India, current behavioural pattern of indian polity,role of International Relations in strengthening the country and it's multilateralism policy towards it's foreign relations.Be aware of the recent constitutional amendments and the ongoing verdicts of supreme court on social and public welfare issues.
You must also be good at history of modern India which includes freedom struggle , Indian rebel against the colonial rule and oppression .

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.careers360.com/university/banaras-hindu-university-varanasi/ma-political-science-course&ved=2ahUKEwjWr5LCupHuAhXhwzgGHTo8B1MQFjABegQIBBAC&usg=AOvVaw2J3_NKSlEAzPpyRZnka7qX

https://www.google.com/url?sa=t&source=web&rct=j&url=https://university.careers360.com/articles/bhu-pet/amp&ved=2ahUKEwjWr5LCupHuAhXhwzgGHTo8B1MQFjACegQIBBAH&usg=AOvVaw0lQeccw73OfEqp0bQ6P53W&ampcf=1

All the best