when initially assigned to an assignment, only a few students were selected and assigned the assignment.
when editing an assignment, the remaining uses are automatically selected for assignment.
what should i select TA permission on admin setting option?
I guess my post-Christmas fog includes not understanding what you are asking? Are you asking about the Admin function of setting and choosing permissions for a TA, or are you asking about assignment setting - specifically the "Assign to" function?
If you could please clarify, I will try my best to answer.