Dear aspirant....!!

JAM requires in depth knowledge of your subject domain, so whatever you read, you should be thorough with it. Do not simply touch each topic, and pass it, spend cconsiderable amount on each subject and try to understand it(in depth and details) .

For petrology :Go for JD WINTER book

For stratigraphy : there's a book called “geodynamic evolution of india” by K. S. VALDIYA, and STRATIGRAPHY OF INDIA by Ravindra kumar.

Paleontology is like SANSKRIT, you have to mug it up,

Books of P. C JAIN AND Ananthraman' s paleontology book will do.

Structural geology : Hakoon Fossen’s book is the best will say it is extraordinary, pdfs are available, if not hardbind book.

Mineralogy : DEXTER PERKINS is the best for all type of entrances, simple language and in depth knowledge. Keep a copy rutley's mineralogy and Dana book.

Also consider Paul. F. Kerr's optical mineralogy also.

For GEOMORPHOLOGY : M. J. Shelby's earth's changing surface.

WD Thornbury book is outdated.

Hydrology : D. K. Todd is best and keep a book of Hydrology by H. M. Raghunath.

Keep studying Km bangar and be thorough with GB MAHAPATRA book.

All the best....!!