Application can be done either online or offline.
Online: This can be done from the IIT websites. There is no need to purchase the hard copy of the application form. While application fee can be paid online, this method does have offline part as well and hence is not fully online. Details can be seen in the information brochure.
Offline: Application form can also be purchased in hard copy as per the details given in the information brochure.
Visit IIT JEE website for further details.
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