Greetings!

Yes, AIR 1 can be achieved in 1 year also but it depend on your efforts and determination . You have to work hard for that as jee advanced is one of the toughest exam to clear. If you will be covering 12 th syllabus+ 11 th backlog along with competitive concept,you can achieve good rank. But for AIR 1, you will be required to solve multiple books and understand each concept thoroughly as well as practically. More you practice, more will be the chance of getting first rank.

You have to make a strict time table and try to do previous year paper and attend mock test regular or weekly to improve your thinking power for the exam.

All the best!