Last month of preparation is very important to score good marks in your exam. 

You should be dedicated and focussed in this last month of your preparation. 

You should revise your syllabus and brush up your concepts. Focus on the topics which carries more weightage in the exam. 

You can use your revision notes.

You should solve as much as MCQs for your practice. Solve previous year papers to get familiar with the exam pattern and to know the type of questions asked in the exam. 

Take mock test series to analyse your preparation level at regular interval of time and to know your strength and weakness. So, that you can work upon them. 

To score good marks try to learn from your mistakes and don't repeat them.

All the Best for your exam!!