In Year End it isn't necessary for the year groups to be assigned for next academic year as all students will automatically go up one year during the Year End process.
However should you wish to assign the year groups for next year this can be done via Admin > Students > Group Updater.
In here you can select the year or form group whose year you wish to set, change the student attribute to New Year for September and then choose.
Once you have clicked Choose you will see a list of the students in the year selected, in the dropdown next to the Check All button select the year they will be in next year, then click Check All (or select the students who are going into that year) and update at the bottom to save.
If there is one student for example who will stay in the year they are in now, once the other students are updated select the year that student is going to be in in September from the dropdown next to check all, tick next to the individual student only and update at the bottom.
Please note once complete you are able to check the information via Reporting > Reports > Students (tab) > Next Year's Form Groups.