You have filled a category by mistake and now need help rectifying it for IIT Madras BS program application via IAT.

It's crucial to reach out to the admissions office at IIT Madras as soon as possible. Explain the situation clearly:

• You mistakenly selected OBC NCL category during IAT registration.
• You cannot provide an OBC NCL certificate because you don't belong to that category.
  
  
  
• In your communication with the admissions office, politely explain the mistake and request them to correct your category selection in the application.
  
  
• Mention the category you actually belong to (if applicable) and any documents you can provide to support your claim (e.g., caste certificate for a different category).
  
  If you belong to a different reservation category, the admissions office might allow you to change your category selection and request the relevant certificate.
  
  If you don't belong to any reservation category, they might allow you to switch to the general category without needing a certificate.
  
  In some cases, they might ask for an affidavit or self-declaration stating that you don't belong to the OBC NCL category.
  
  
  
• Once you have contacted the admissions office, keep a record of your communication (email or phone conversation details).
  
  
• If they require any further action from you, respond promptly to avoid delays in processing your application.
  
  https://www.careers360.com/university/indian-institute-of-technology-madras
  
  I hope it helps!