It might be a problem for you to go ahead with nutrition and diet course as you have not completed your graduation from science stream.
Dieticians are experts in clinical and nutritional matters. They study people’s diet and try to promote good health by advocating a healthy diet that might differ from person to person. Dieticians work in hospitals, nursing care facilities and physician and health practitioner offices, focusing on patients' health through diet and nutrition.
You need to clear Registered Dietetics (RD) exam by the Indian Dietetics Association (IDA). You must be a life member of IDA before taking the RD exam.
Registration for IDA membership and application forms for the RD exam can be downloaded from the official website of IDA.
Eligibility for UG course –
You should have passed 10+2 with science subject from any recognised board.
Eligibility for PG course –
You should have passed graduation with science subject from any recognised university.