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)
Mayank vedwal Vedwal Best Answer
For igneous petrology u can build up your concept through J. D. winter book . This book is best for all competitive exams like IIT JAM and GATE . For further knowledge u can go for Myron G. Best.