Instead of a simple Split, I'd suggest that you look at a Regex: VB.Net - Regular Expressions - Tutorialspoint
] - they can be a lot more flexible and powerful. But they are hard to learn.
Instead of either, read the file as lines, and process each line, discarding blank lines
When a line starts with "* GROUP No." it's the start of a Group, and it's trivial to get the group number with Substring and TryParse.
The following line should start with "RESULT":" and again it's trivial to get the result code.
Collect the Remark and Example data, ignore blank lines
If the result code is FAIL, then collect the additional info, otherwise ignore it until you get a fresh GROUP.
Me? I'd create a class to hold the info, and create a new instance to fill in each time I got a new Group - adding it to a collection such as a List. Getting all the info I can, because at some later point the task will change and require some of it, and it's easier to organise it to start with. The additional data for a FAIL code would be a collection of it's own within the class I created.