Hello,

Firstly official notification of BHU PET of 2021 isn't released yet, if we go through last year information bulletin,  it states that candidates need to be well acquainted with the graduation level studies of political science though there isn't any prescribed syllabus as such in detailed manner, you should go through your graduation level books thoroughly along with emphasis on political theory, current behaviors of Indian polity, international relations, constitutions of India, its freedom struggle and fight against the colonial rule, the constitutional amendments and verdicts of supreme court etc, to cover these topics you can refer OP Gauba book and M Laxmikanth's Indian Polity, the entrance test is conducted for a duration of 120 minutes for 120 MCQS carrying 360 marks, to know more details regarding this go through previous year paper at http://bhuonline.in/old-qus-paper-2019.html