I planning to upgrade Sybase ver 5 to Sybase ver 12.

Is there any tool that I could use for analysis and very helpful for this upgraing process?

Any suggestion for strategy planning that I should think about for upgrading

Version 5?? That's very, very old. I think the best way is to export all the tables, recreate them in ASE12 en import the data using bcp.

I'd recommend skipping Sybase 12 and go for ASE 15. Version 12 is (nearing) end of support.