Citizens of most countries need a visa to travel to India. Information on how to obtain a visa may be found at the nearest Indian Embassy or Consulate.
In the US, the Indian Embassy website is http://www.indianembassy.org/. This site will point you to Travisa Outsourcing, a company contracted by the Indian Embassy and Consulates in the US for handling visa paperwork. Their site provides direction on how to apply for a visa.
If you plan to do any sightseeing or tourism as part of your stay in India, you are advised to apply for a 'tourist' visa. If you are planning to come to India strictly for ISER and do not plan to do any sightseeing or tourism before or after the conference you are advised to apply for a 'conference' visa.
Invitation letters to the conference (required for a visa application) have been mailed to a large number of prospective ISER participants. If you need such a letter and have not received one, please email email@example.com. Make sure you take copies of the three certificates, clearance from the Indian Ministry of External Affairs, from the Indian Ministry for Information Technology and Commerce and the clearance from the Home Ministry with you when you apply for visa.