I see no red combs, so all are likely pullets. But to be absolutely certain, closeups of combs wattles, neck feathers, saddle feathers and tail feathers are necessary to see the detail we need.
Usually, by age six weeks, cockerels have conspicuous red combs and wattles. By ten weeks, they have conspicuous pointy saddle feathers and neck feathers, and the beginnings of curved sickle tail feathers.
Pullets retain pale pink combs until point of lay.