There are many types of visa whether you need one for work, transit or holidays. We will focus only on those for travelers which are of two type: e-tourist visa and regular tourist visa. The main difference between the two is the duration of the visa.
E-visa: The e-visa lasts for two months and you can only enter the country two times during these 60 days. To apply you should fill in the form on https://indianvisaonline.gov.in/visa/. On this website, you can find the e-visa category. After filling in the form you will receive your visa during the next 72 hours by email. However, it is recommended to apply at least 10 days before your trip in case there is a problem with your application or if there are too many demands. It is easier than the regular visa because everything can be done online even the payment (around 90 euros).
Regular Visa: The regular tourist visa is up to 6 months maximum with multiple entries. The website to fill in the form is the same as the one for the e-visa (https://indianvisaonline.gov.in/visa/). The difference is that you have to send or drop the application with others documents (your passport, two ID photographs…) to the Indian embassy. For the two photographs, you should be aware that it is not the French standards so you will probably have to do it either at the Indian embassy or at a photoshop.
The procedure can take a long time as they ask for any information about you and your trip. We advise you to do it on internet explorer rather than any other web browser as it may not work otherwise. Moreover, it is highly advised to check the website http://vfsglobal.com/india/france which will give you all the information you need to fill in the application and send it.
If you drop it directly in Paris you will receive it within four days, but if you choose to send it you will get it around the next 10 days. The price is approximately 130 euros.
If you want to go to north India like Sikkim area, you will need an inner line permit for which you can apply on the same website.