Hello student,
Some important documents are follows:-

• Recent Passport size color Photograph
• Valid identity proof (like Aadhaar Card or Passport or Ration card etc.
• Valid proof of Date of Birth (like Aadhaar Card)
• A valid proof of Residence.
• class 8th marksheet or Self Certificate (in case of secondary course).
• Class 10th marksheet (in case of senior secondary course)
• Social Category/Caste Certificate
• Ex-serviceman Certificate
• Disability Certificate
• Fail marksheet of previous Board, failing which Transfer of Credit (ToC) marks will not be updated in NIOS result.

Hope it helps you
Thank you