z/OS 1.6 was released by IBM in Q3/2004 and is out of maintenance since 2007 ( http://www-01.ibm.com/software/support/lifecycle/index_z.html ),
otoh Adabas 6.2 (you didn’t even say which level of Adabas 6 you are running) support was discontinued in December 2000, so there’s a huge gap.
The general rule is that Software AG products always support operating system levels available at the same time.
When you look at the Natural 3.1.5. release notes, for example (available in empower) it reads:
“z/OS 1.1 (Natural Version 3.1.5 supports z/OS to the same extent as it supports OS/390; new features of z/OS
will be supported only as of Natural Version 4.1)”
so basically you are on your own to try it, it might work, but no guarantee,
you will have to raise a support incident if you need an “official” statement.
There are no specific migration procedures, as another general rule you always
have to redo any installation steps which pull in operating system specific stuff,
like re-assembling COM-PLETE’s or Entire System Server’s JES interface etc.