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. However, this method requires a few things like print-out, fee and others to be sent to the IIT Madras postal address. Details can be seen here.
Offline: Application form can also be purchased in hard copy as per the details given here.
Visit IIT JEE website for further details.
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