File an RTI application addressed to the Public Information Officer of the exam conducting body.
Mention your name, roll number, registration number, exam name and exam date clearly.
Pay the RTI fee through the mode the body accepts — the reply must come within 30 days.
Many bodies, including SSC, have published specific procedures for OMR and score disclosure.
You can also ask for your marks breakup and the final answer key in the same application.
Keep a copy of your RTI application and payment proof for follow-up.