Hello! Thank you for reaching out to Careers360. Regarding your query, if you didn't join the seat offered in Round 1 and also didn't register for Round 2, your eligibility for Round 3 may depend on the specific guidelines set by the examination authority. Generally, candidates who have not accepted their seats in earlier rounds can still be eligible for subsequent rounds, but it’s essential to confirm this with the official guidelines or helpline of the examination authority for accurate information. If you need assistance with anything else or further clarification, feel free to ask!