Can a candidate qualifying as reserved be selected on UR seat if he meets out UR cut-off later

In the Staff Selection Commission (SSC) exams or in an exam of any recruiting agency, if anyone who is qualified as a reserved candidate earlier at any stage say the Combined Graduate Level (CGL) Exam, or the Combined Higher Secondary (10+2) Level (CHSL) Exam, or the SI Delhi Police and CPO Exam, or the Civil Services Exam (IAS Exam) which is conducted by UPSC, or any other exam conducted by any recruiting agency, he can’t be selected for a UR seat even if he scores meeting the UR cut-off in the final result. He will only be considered for the category against which he was qualified earlier.