Hello,
Yes you can prepare for class 11th exam but it requires a lot of dedication from your side.You need to make a proper timetable and give ewual time for preparation of each subject.You need to concentrate on your textbook only as most of the questions are based on your prescribed textbooks.
Make proper notes of important topics and formulas.Practice as much as you can as it will make you easy to score in class 11th exams.Avoid distractions.
Make sure that all your doubts are clear if not then consult to your teacher or coaching institute.
Good luck.

In order to prepare for class 11 in one month you need to be focused and dedicated. You should make your time table according to your comfort. So, that you can easily complete your course and you get enough time for revision. 

You should focus on the topics which carries more weightage in the exam. 

Try to solve previous year papers to get an idea about the level of the questions asked in the exam.

 

All the Best!!