I have passed class 12 with arts and graduation in BCA. Am I eligible to study B.Ed from College of education Guwahati?

Yes, you are eligible to study B.Ed from College of Education, Guwahati. You have completed your graduation, this means that you fulfil the eligibility criteria for B.Ed. Thus, appearing of entrance exams, if needed and following the admission process, you can do your B.Ed.