MBA students have to select their specialisation or electives in the second year. Choosing the specialisation is not directly related with your graduation subject. If you have any particular career in mind, then you can choose the course accordingly. Otherwise, based on the experience of studying first year of MBA course and inputs from fellow students and professors. For more idea, download and read the following ebook:

www.bschool.careers360.com/which-specialization-catalogue-mba-courses-india