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)
Jeevesh magnani
I will be honest, modern physics isn't my strong hold. And for the same reason, I would refrain from answering this question as I wouldn't like to give you wrong direction which can hamper your concepts.