Can I register for this course? But I only have a diploma in financial management staff level 2 and my English is not very good

Dear, Taleen. There are 2 options for a management master: Master of Arts in Management (MA), when you do not have too much working experience, and Master of Business Administration (MBA) when you already have some experience. Is your diploma a Bachelor Degree and do you have working experience? In that case you can apply for the MBA, otherwise you can achieve a MA.

About the english requirement, you need at least IELTS 6.0, or you can take a preparatory course in Saxion before your master:

https://www.saxion.edu/programmes/preparatory-course/preparatory-semester

https://www.saxion.edu/programmes/preparatory-course/preparatory-year