Is it possible to rename an index in the same way sourcetype and source can be renamed with props and transforms.
from a similar post - You can't really rename an index, but you can create a new index with the name you want (via indexes.conf/GUI) and move the data from the old index to the new index.
You would need to stop Splunk, then move the $SPLUNK_DB/ directory to $SPLUNK_DB/ and then start Splunk. That should be all you'd need to do to get the data in the new index. Keep in mind any searches that reference the other index will need to be changed.
http://docs.splunk.com/Documentation/Splunk/6.1.4/Indexer/Moveanindex
Assuming your data is not cooked yet (it hasn't gone through a Heavy Forwarder already for instance) you can do this in your indexer or in a heavy forwarder:
transforms.conf
[renameindex]
REGEX = .
DEST_KEY = _MetaData:Index
FORMAT = newindexname
props.conf
[sourcetype, host or source stanza]
TRANSFORMS-index = renameindex
See this: http://docs.splunk.com/Documentation/Splunk/6.6.1/Admin/Transformsconf#KEYS: