Hello,
ANM or Auxiliary Nursing and Midwifery is a one year diploma course which can be only applied by female candidates. ANM focus on the study of health care of various individuals.

GNM or General Nursing and Midwifery is a 3.5 years diploma course. It is for both male and female students. It deals with the education of nurses in general health care, nursing, and midwifery.

Some top colleges offering courses in diploam nursing are

• Indian Medical Institute of Nursing
• Armed Forces Medical College , Pune
• Indian Army Military (IAM), New Delhi
• Guru Teg Bahadur Hospital , New Delhi
• Bharat College of Nursing
• Aligarh Muslim University (AMU), Aligarh

Hope it helps