You might have some difficulties, as with any migration.
Like Justin said, test it, test it and test it again. There is absolutely no other way around it. Especially going from one OS to another.
Other than that, for this migration there is really nothing special about it, export DB, reimport DB, correctly configure CMOD, and that's it.
I didn't know that TSM 6.5 exist!!! I though that it went from 6.4 -> 7.1 !
Oh... one important thing.... PLEASE do not use TSM 7.1.1... go directly to the latest version. The 7.1.1 is buggy as hell... so do you a favor, go directly to the latest fix pack for Oracle/Linux/CMOD and TSM.