ORACLE Shifting from from one version to another I have RHEL5 server with Oracle Home actual location is SAN, which is mounted on this server.

Now for few Reasons I have one more Server with RHEL 6 64Bit.

I will map those storage LUNS there.

What are the various ways to migrate and what are the advantages/disadvantages ?

Point 1: Take backup from old system and go for new install no new server ?

Point 2: Directly Map LUN and with few changes I can achieve this ?

Can I go for creating control files and copy and backup on new server and start making changes in spfile and pfile and go for changes ??
Since you upgrade your OS, at some point you need to relink your Oracle software. In that case, easiest is to make a new software installation on the new server. Unmount the luns where the database is located from the old server and mount that on the new server where the database files should be mounted on the same locations as on the old server.

I hope that the ORACLE_HOME is not on the same lun[s] as where the database is located. If ORACLE_HOME does exist on the same LUN[s], make sure to create the new ORACLE_HOME on a different PATH and make sure that config files like /etc/oratab and listener.ora reflect this change.

This should give the quickest migration.
If there is to be done more than just re-mount the LUN[s], make sure to have a capable DBA involved. That will save you a lot of downtime and problems.