5-10 minutes doesn’t count as repetive (in my books) - something that a child does for hours. It could be stacking blocks, sorting something or coloring, or spinning wheels of a car.
Absoultely - as Mamaof3 said - it can start early as even 3-6 months.
I would encourage that you learn some of the activities that they teach in therapy and apply them at home. You don’t need to do it all day but every 10 minutes of every hour - try to engage your child in a conversation in animated play situation.
Whatever you are doing in the home - talk about it.
“Look at mommy put the laundry in. These clothes are dirty - these are clean. these are wet - these are dry.”
"Lets Stir the sauce - can YOU stir the sauce? "
Walk up to the window - *“what the weather for today - is it sunny, cloudy? windy?” *
Don’t worry if he doesn’t understand at first. He will iA.