Preparing for MA Economics entrances for JNU and DSE will need immense concentration and dedication. You will need to prioritize to keep everything in balance. Here are some things you can go through:

• The core subjects include Mathematics, Statistics, Microeconomics, Macroeconomics and Econometrics. Select any 3 out of these 5 subjects which you feel are your strengths.
• Revise the basics from your graduation notes and practice past year exam papers.
• For the subjects you feel you are weaker in, revise the basics. Do not spend too much time on them. 
• Practice questions from past years. 
• Analyse the topics in which you are lagging behind and try to read those in detail. You can also skip some topics too.
• For Statistics, focus more on Permutations and Combinations, Probability, Discrete and Continuous Random Variables.
• DSE requires a mathematical approach and proper concentration. So practice past year papers and do not forget concepts.

The books you can refer to are: Dornbush and Blanchard for Macroeconomics. Hal Varian, Nicolson, and Pyndick for Microeconomics. Hammond and Chiang for Maths. SC Gupta and Miller for Statistics and finally Gujarati for Econometrics.