Only If you have passed B.A. (Hons.) Examination in Political Science from Delhi University with minimum 60% marks then you are eligible for direct admissions.
If you have 50% or less in the same you need to appear for entrance.
If you have done your bachelors from University other than Delhi University, recognized or equivalent to Delhi University with minimum 55% marks then also you have to appear for entrance
In all other cases you have to appear for the entrance except the one mentioned above.
You can check complete eligibility here
https://sol.du.ac.in/my/eligibility.php