hey ebin

actually the syllabus a changed a bit but not that much . i think solving previous year paper is quite usefull and rather i will say it is important as well to solve the previous years papers . i will suggest you to buy arihants previous years IIT JAM solved papers as i found it quite useful .especially focus on last 4-5 years questions as syllabus had changed very less or minute in that time .also solving them will give you the list of important formulas and concepts 

best wishes