Although Infinity doesn’t have a reporting feature just yet, there are several ways how you can present your data to achieve what you need.
I would suggest having one folder for each month - for example Current Tasks (March), and then have Archive February, Archive January, etc.
Once a month is completed, you can drag and drop the tasks to the corresponding Archive folder (you can use multiple select to help you do this faster). Or you can simply duplicate the same folder without items each new month. (use it as a template of sorts)
In each folder including the Current Tasks, you can have 6 tabs - one for each employee. Now you will need Members to assign tasks and a checkbox to mark tasks done. Of course you can add all the other attributes you need, but those will be essential for this idea. Then in each tab you can filter out each person’s tasks. So you will have a tab for John, Mary, Peter, etc.
This is how to set up the filter:
And this is how it can look after you group the columns by Done (checkbox):
This is great because each person will be able to focus only on their tasks, and you will be able to have a clear image of what each person completed each month.
What do you think? Could something like that help you achieve what you need?