It appears you are getting ready to visit the United States. In the U.S. an International Driving Permit (IDP) is not required but is often recommended. As a foreign visitor you need a valid driver's license from your home country. The IDP is helpful because it is written in several languages and verifies that you hold a valid license in your home country.
As for obtaining an IDP in India it appears that you can apply and pay the fee for the permit at Regional Transport Office in India. You need to bring supporting documents of: valid driving license, attested copy of birth certificate, valid passport and visa, attested copy of address proof and two passport-size photographs. You must apply in person because you will be interviewed and need to pass an international road signs test. It typically takes two working days to process the application. You will need to check to see how long the IDP is good for; once it expires you will need to apply again.
The Indian Automobile Associations are also authorized to issue IDPs to their members. Our Learning Center can give you more information you might find helpful for your visit to the U.S.