Jamboree is the best institute for GMAT preparation in my opionion. Especially Amit Sir. Have never met/seen a more energetic, cooperative teacher . Even if you call him at 2 in the night for doubt clearing, he would never say a NO ! Hiten Sir in the computer room is the best guidance for how to go about this exam. Their library has enough material to get 700 plus is GMAT. All you need to do is go there in the library study as much as you want . So, whenever you go to Jamboree , make sure that you join the Amit Sir batch since there are more teachers too but Amit sir is the best !