Hi,
You have two choices since Gentran 6.0 has two mapping tools. One is the so-called "old mapper" which you are using now in 5.3. The other one is called the Visual mapper which is basically the mapper from Gentran NT incorperated into Gentran for Unix 6.0
1. For upgrading your maps to the "old mapper" in 6.0, copy your .map files from your 5.3 environment to the new maps directory and change the extension into .vmp and compile them.
2. If you want to upgrade your maps with the Visual Mapper you will have to re-write your maps from scratch using this new mapper. This mapper is quite different from what you are used to right now but it all becomes clear quite quickly once you work with it. You can follow a short course (3 days) provided by Sterling Commerce if needed.