Hello Sandip,

Passing JEE without coaching is all the matter of one's capabilities and resourcefulness and hard work. Of course it is possible to clear JEE without coaching. What coachings basically do is they polish your skills and often provide organized study material which you will have to resourcefully arrange in case you are not taking coachings. If you believe that you can do without coachings and that you don't need everything sorted and you can manage to study and to an extent, excel, in most of the part of the syllabus then you can certainly step out of coaching. 

All the best.