query about grouped data

i have dataset (image attached) and i want to group data for every 5 rows...

[jgg]

I think you need to provide more information; what do you mean by group? There are lots of different ways to group and combine data, and it's unclear what you're trying to do.

The simplest way to start would be just create a new vector v = [1:n] where n is the number of rows, then create grouping variable g = floor(v./5). You can then go from there to do whatever you want to do.