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)
Mahak
For jest exam you check the site of various institutes. In this different institute have different criteria like some call till 50 rank, some call till 100 and some iisers call till 400-500 rank . So you check the site for various institutions.