The government of India issues conference visas for participants in conferences. You can find out more information about the application process here.
To apply for the conference visa, you will need an invitation letter from us. Please contact us with information about your passport (full name, country issuing it and passport number), whether you have a paper accepted to the conference, or otherwise, a short resume or a link to your professional homepage, and your address that you would like us to include in the letter (optional).
You should also include a copy of the government clearances in your visa application.
The government of India also issues "e-visas" for travellers "whose sole objective of visiting India is recreation, sight seeing, casual visit to meet friends or relatives, short duration medical treatment or casual business visit." If you are just accompanying a conference participant, this is the visa you should apply for. Please find more information about this (simpler) process here.