Yes, You can complete the 11th syllabus in 5 months by proper concentrating on your study. Make a structured study plan in which you can write what you have to study every day in separate columns. You can also prepare a short note of every chapter which you need during exam times.
.Remember: .Always start preparations with the basic concepts, then go to intermediate concepts and finally to the tougher concepts.
.Hope it helps you.
.THANKS.