hi,

sss of jnu stands for school of social sciences, where, sis stands for school of international studies. both of the centers offers m.a in economics, but the syllabus of the course is different, sss of jnu offers m.a in economics while sis of jnu has m.a in economics course with specialization of world economy.

admission is based on score in entrance test, candidates would be shortlisted based on performance in entrance exam.

No viva voce examination is held for admission to any programme except for admission to  M.Phil and Ph.D. The candidates are admitted on merit score on the basis of their performance in the Computer Based Test (CBT) and the deprivation points added to their score in accordance with the approved admission Policy and Procedures of the University.

however if the university authority want to change the pattern and add the interview sessions you  have to attend the interview as well. so regularly follow the official website and check the upcoming notifications.