CAT Application: Name Mismatch Between CBSE Marksheets and Government Documents

My CBSE Class 10 and 12 marksheets contain only my first name, without a surname. Later, I legally updated my name in my government documents to include my surname and have a valid affidavit supporting the name change. While filling out the CAT application form, which name should I enter—the updated name as per my current government documents or the name mentioned on my CBSE marksheets?