At what age can pullets be introduced to cockerels?

[Chickens14]

I have a flock of Bantam Faverolles they are 6 months old.
Then I have 4 pullets that are 3 months old...... At what age can
I introduce the 4 pullets to the flock that is 6 months old. I am thinking
the young ones should be 6 months before I put them in with the flock with
boys that are older....
What are others experiences...

Thankyou ~~Jen~~

 

[Mahonri]

Younger ones can integrate at 16 weeks, but I like to wait till they are 20 weeks old.