How to pass value of multiple checkbox to a model?

i've in a rails form a multiple checkbox values. I need to pass this values (if checked) to a model that create the categories.

I've this in form.html_erb

<%= form.check_box :categories, {multiple: true}, "U6", nil %>
<%= form.check_box :categories, {multiple: true}, "U8", nil %>
<%= form.check_box :categories, {multiple: true}, "U10", nil %>

I want to create TeamCategory with the values checked. Something like this?

def create_tournament_team_categories
    VALUE_CHECKED.each do |name|
      team_category = TeamCategory.where(name: VALUE_CHECKED).first_or_create
      self.tournament_team_categories << TournamentTeamCategory.create(team_category: team_category)
    end
  end