Yes. Very much possible. Coaching are helpful but you can do it on your own also.
- You must get the prescribed books (Search Google to get an idea).
- You must be highly motivated. This is a must. Coaching provide you a competitive spirit only. Rest you can get very good online videos for lectures.
- The best way to learn is peer learning. Groups are more successful every where. Make a group of like minded people. Ask every one to make one question paper per week on any topic of common interest.Testing is the best form of learning as shown by many leading researchers.
- You can join any test series for regular motivation and checking your progress.
- Many toppers (Top 100) do not prefer coaching as it is too general for them. They do join but go very less or attend important classes and test. Coaching is a distraction also for the ‘romantic’ ones. But good students make good use of every thing.
Don’t worry, you can top with self study let alone getting into IIT.
PS : You do self study only. Teachers only help you to find it in with in your self. A good teacher only saves your time.Also motivation is a key factor. Motivation is more required from a teacher than knowledge.
Take your motivation here. Remember to replenish your stock of motivation regularly.