Yes, you are eligible to do M.Sc in Nutrition and dietetics after B.Sc(bt,mb and chem). It is one of the well paid job in India and to know more about this course, top colleges offering nutrition and dietetics  and its admission process , recruiting companies and many related information,  click on the following link,

"Nutrition and Dietetics Courses, Subjects, Colleges, Syllabus, Scope, Fees, Eligibility" https://www.careers360.com/courses/nutrition-and-dietetics-course

Hope this helps you.