@Vinit Pandey, for the encrypted files under HDFS encryption zone. They are only allowed to rename within the same encryption zone. You may copy to/from encryption zone which had an additional decrpt (or encrypt) overhead compared with rename.
Please refer to the document for more details:
"HDFS restricts file and directory renames across encryption zone boundaries. This includes renaming an encrypted file / directory into an unencrypted directory (e.g., hdfs dfs mv /zone/encryptedFile /home/bob), renaming an unencrypted file or directory into an encryption zone (e.g., hdfs dfs mv /home/bob/unEncryptedFile /zone), and renaming between two different encryption zones (e.g., hdfs dfs mv /home/alice/zone1/foo /home/alice/zone2). In these examples, /zone, /home/alice/zone1, and /home/alice/zone2 are encryption zones, while /home/bob is not. A rename is only allowed if the source and destination paths are in the same encryption zone, or both paths are unencrypted (not in any encryption zone)."