Please check the following with your doctor, especially if you are planning to travel to rural areas. It is recommended (but not legally necessary) that any traveller to India be protected against the following:

Poliomyelitis
Hepatitis A
Typhoid
Malaria - Anti-malarial tablets and precautions against insect bites
Meningococcal Meningitis
Rabies
Hepatitis B
Tuberculosis
Diphtheria
Measles/MMR  

Yellow fever certificates are required if you have been to an infected country (mainly certain parts of Africa and South America) within the previous 6 days