Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Aparna 1
You can do the study of Flip-flop from Book of titled "Digital Electronics Principles, Devices and Applications" by Anil K. Maini. The book is available online also. Go through chapter no. 10 for details of flip-flop. Just review of flip-flop for your reference- Types of flip-flop 1. SR flip-flop 2. JK flip- flop 3. D flip-flop 4. T flip-flop