This post focuses mainly on motivation.
Most students appear for IIT-JEE because of parental pressure ! Some do that simply because their "friends" are preparing for JEE !!
NO. This is should not be the reason for you to appear for the most prestigious exam of India. You are simply increasing the crowd. And it is highly likely that you won't be able to crack the exam.
There must be some self motivation, a desire to do well, a hunger to study in the Premier Colleges of India, an ambition to go ahead of others, a zeal to prove yourself.
Here is something to motivate you.
The feeling when you crack JEE is different.
The society looks you with respect. You are thought to be as a born genius. People start talking about you. You start feeling like a celebrity. Aunties would say "Wo to brilliant tha hi, uska to IIT me selection hona hi tha". Your photographs appear in the newspapers. Relatives start respecting you. You get numerous phone calls from friends/relatives/teachers, congratulating you and wishing for your success. You get party demands from everyone you can think of.
This feeling is great. "I have proved myself, I am an IITian now."
You will also find tonnes of people who are jealous of you. But feel lucky - everyone doesn't get the privilege to have "Haters".
During your journey, many will misguide you, demotivate you by telling you that "IIT's are no more that prestigious what they used to be. Now PQR College is more in demand" or any other thing of that sort. But, you must be wise enough to shut your ears and move on with even a higher confidence level.
IIT's are IIT's. Best Colleges of India. They have ruled the "Top Engineering College of India List" from years.
Confidence and Motivation are the key to cracking JEE.
Another point you must keep in mind this that "I want so and so rank so that I am able to get XYZ branch in IIT-Z". That "so and so" must be clearly defined from day 1 itself.
You must be aware of the opening and closing ranks of the XYZ branch in IIT-Z so that your mind is set to work accordingly.
Don't just blindly prepare for JEE. Have a clear-cut target in mind and struggle for it.
All the best.