Hi Kumar

Few books i would like to suggest you for socialogy

Sociological Theory’ by George Ritzer.

Ambedkar, Gandhi and Nehru most importantly.

JNU then you can purchase handwritten notes from the book stores nearby JNU. Apart from this, you can practice sample and previous year papers as these will be letting you know about all the important question and difficulty level of paper.

Also, you can download last 3 year question papers from belowlink -

Question Paper

Coming to political science

Sushila Ramaswamy, C.L.Wayper. For Indian Political Thought read either Thomas Pantham or B.R.Mehta. For Indian Politics Oxford Companion to Indian Politics and read book by Bidyut Chakravarty and Rajendra Pandey on indian government and politics,Also follow current affairs.

Broadly in JNU MA entrance questions are asked from Classical Political Philosophy,Indian Political Thought, Indian Politics, International Relations.

Hope this helps

Regards