Hello Mala,
For admission in JNU under Phd in any stream you need to fill the form for JNU entrance examination which will be available by February 2019. Then you will be getting your admit cards for the examination. After appearing the examination; if you clear the cutoff then you have to appear for the viva voce. Claering both stages you will be eligible for admission

To pursue pH.d in political science must have the master degree,there is no age restriction M.phil degree and 60% marks in M.phil part1 or master's degree with 2nd division with no less than two research production.NET,RAT,tata institute of social sciences,indhira gandhi national open University,Madras school of political science,Christ University are the entrance exams depends on various exams admission will starts. I think go through this link it will help u https://collegedunia.com.

Hello

Jawaharlal Nehru University has changed the entrance examination process for the academic year 2019-20.

The entrance examination will be held in May and the format of the exam will be Computer Based test. Format of the exam will be Multiple Choice Questions.

Selection for the PhD program will be based on the entrance exam which will be conducted in MCQ format and a Viva Voce Subjective evaluation.
70 percent weightage in the selection process will be given to the entrance exam followed by 30 percent weightage to a Viva Voce Subjective evaluation.

Prospectus has not been released by the University so we will have to wait for the prospectus to checkk the detailed eligibility criteria and the admission process.
Prospectus and the exact dates of the admission process are expected to be declared shortly by the University.
Stay Updated.

Good Luck!