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)
Ruby negi
you can go through the solution of vaishali. and for any doubt you can ask.you have to know these types of partial derivative in thermodynamics. and also remember all Maxwell's equations.