You have been raising chicks in your house for about the last six weeks. You are probably over them in your house. So when can you move chicks outside?
For 6 weeks you have made sure those little chicks have been warm in their brooder. Time to start putting those little fluff butts outside.
Depending on your temperatures you can start giving them outside time before they are 6 weeks old.
I do not recommend putting your chicks in with your adult birds if you have them. There is going to be aggression, and your chicks might not make it out alive sadly.
You can also start by putting them outside in their brooder (minus a heat lamp).
I like to make sure that the forecast shows warmer nights, no below-freezing temperatures. If they aren't completely feathered out I just put them out during the day and bring them in at night.