Tourist can enter in India by different modes of transportation:
You need visa before entering in India.
India Visa Info
An Indian visa is issued by the Indian embassy or a consulate. In many countries, the job of collecting the application form and fees has been outsourced to a visa agency. Check the website of the Indian embassy or consulate nearest to you (depending upon the country from where you are applying).
The general document requirements for obtaining a tourist visa to India are as follows:
A valid passport that has a validity of 6 months remaining and at least two blank visa pages.
Proof of residency, if you’re not applying from your home country. Check with the Indian consulate in your country as to what factors apply in these cases.
Two passport-size photos (2″ x 2″) that were taken within the last 6 months. These should be without glasses.
A completed Indian visa application form.
Fees for the Indian visa, as stated on the visa website for your nationality and the country you are applying from.
You must fill in your India tourist visa application form online and print a copy afterwards. Be very careful when completing the form as even a minor error in spelling or a typo can get your application rejected. All names and addresses should match your passports and other identification documents that you submit along with your application.
Other than your passport, don’t submit any original documents. Send color copies instead, as the embassies warn that they are not responsible for any original documents lost.