Hi Ankur ,
I didnt write a specific document for this, as we usually do Linux migrations. Our customers use Linux mostly. S oI have did several Solaris to Linux and HPUX to Linux migrations, I do Exadata migrations mostly in these days..
Here are some migration stories from my blog:
http://ermanarslan.blogspot.com.tr/2015/03/exadata-ebs-11i-migrating-ebs-11i-to.htmlhttp://ermanarslan.blogspot.com.tr/2015/02/rdbms-11gr2-windows-single-node-to.htmlhttp://ermanarslan.blogspot.com.tr/2014/02/oracle-ebs-on-exadata-x3-database.htmlhttp://ermanarslan.blogspot.com.tr/2015/02/exadata-ebs-11i-exadata-migration-from.htmlI suggest you to start with doc bytheway..
R11i / R12: Oracle E-Business Suite Upgrades and Platform Migration (Doc ID 1377213.1)