Please find attached the initUAT.ora
initUAT.ora1. I removed the spfile
2. I edited parameter 'db_recovery_file_dest' from '/backup' to the full path of backup '/backup/PROD/backupset/206/07/14'
3. The I connected to RMAN
4. connect auxiliary /
5. I did RMAN duplicate target database to UAT backup location '/backup/PROD/backupset/206/07/14'
6. Then it worked.
i noticed since I changed the db_recovery_file_dest to the full path of backup location it worked.
That's all I did.
I did not specify the logging in rman command else I could have uploaded the RMAN log file