By a journey to India on 6 months or longer recommend protection against the following infections:

Diphtheria
Diphtheria is a serious throat infection, which infects from person-to-person through the air. The vaccination should be less than 10 years old otherwise a booster is needed.
Read more about diphteria here.

Tuberkulosis
The vaccine against tuberculosis, BCG, is recommended to people stationed in high-risk areas for more than 6 months, who have not been previously vaccinated. The vaccine contains live bacteria which produces a small wound, as well as scar after healing. The whole process takes 4 to 8 weeks.
Read more about tuberculosis here.

Hepatitis A (infectious hepatitis)
Infectious hepatitis infects through contaminated food and water. Vaccination consists of two injections about 12 months apart, which protects for up to 25 years. The first vaccination protects for 12 months. 
Read more about hepatitis A here.
The hepatitis A vaccine can be combined with the vaccine against hepatitis B

Hepatitis B
Hepatitis B infects through blood, sexual activities and, in small children, through saliva. The vaccination consists of 2 vaccinations about 4 weeks apart and a third 6 months later. The protection is for at least 25 years perhaps life long. 
Read more about hepatitis B here.
The hepatitis B vaccine can be combined with the vaccine against hepatitis A.

Meningitis
Meningitis due to meningococcus bacteria infect from person to person through the air. The vaccine protects against infection for 3 years after 1 vaccination. There are two vaccines: One protects only against type A and C. The other protects against A, C, W135 and Y and is used for travel to Saudi Arabia (especially Hajj) and West Africa.

Read more about meningitis here.

Rabies
The vaccination consists of 3 injections at day 0, 7 and 28 and must therefore start 4 weeks before departure. Vaccination protects for 5 years. If exposed to rabies, the "post-exposure" vaccinations are reduced from five to two if immunized before being bitten with 3 injections. 
Read more about rabies here.

Tetanus
Tetanus is a complication to wounds contaminated by soil. If there has been a vaccination within the past 10 years it is not necessary to give a booster in case of wounds and accidents. Tetanus vaccinations are usually given in combination with diphtheria vaccine. If you are previously vaccinated, the vaccine can be given right up to departure.

Typhoid
Typhoid is the most serious of the Salmonella infections. There are two types of vaccine: 
1. Vaccine for injection,  one  vaccination protect up to 3 years. 
2. A live vaccine in capsules, which is swallowed. Three capsules are taken 2 days apart and provide protection for a year.
Read more about typhoid here.
Read more about diarrhoea here.

Yellow fever - transit
Certain countries without yellow fever require a valid yellow fever vaccination certificate if you arrives (even in transit) from a country where yellow fever is present. 

If you arrive from a country without yellow fever, there is no requirement for a yellow fever vaccination.

Read more about yellow fever here.

Malaria in India
Risk of malaria is seen on the map below. The choice is between Malarone, Doxycycline or Lariam. Protection against mosquito bites will reduce the risk further. 
The distribution of malaria can be seen at the map below.
Read more about malaria here.

The information on malaria risk in individual countries are based on the sources found here

Japanese encephalitis
Japanese encephalitis is caused by a virus spread by mosquitoes. Vaccination consists of 3 injections with 2 weeks apart and protects for up to 2 years. Vaccination should start 4 weeks before departure. 
Read more about japanese encephalitis here.

Recommended vaccinations Starting Diphtheria 1 day Tuberkulosis 6 weeks Hepatitis A (infectious hepatitis) 1 week Hepatitis B 3 - 4 weeks Meningitis 1 week Rabies 4 weeks Tetanus 1 day Typhoid 1 week Japanese encephalitis 3 weeks Yellow fever - transit 10 days Malaria in India 7 days 6 weeks When to start vaccinations before leaving::