Hi,
You can link to a specific tab by adding the sTab query string parameter to the URL like this:
/Lists/DFFS_TestList/EditForm.aspx?ID=52&sTab=5
If you want to show a specific tab when entering EditForm from this link you can add another query string parameter like this:
/Lists/DFFS_TestList/EditForm.aspx?ID=52&sTab=5&ShowChangeDatetab=1
Now create a rule in your EditForm that triggers on “Selected tab index / Tab unique ID” = “ShowChangeDatetab=1” and show / hide your selected tabs.
Alexander