Brother kicked out

Wow. I hate family drama. Leave him a text on an app or social media, say "it's your brother/sister, let's meet up. I miss you and I'm worried." that's what I would say.

Shes said its going break things

it's really not going to break anything. talk to her about this and tell her she's overreacting (as long as you'll still be safe). it's not safe to kick your brother out, especially now, adult or not.

will they be able to arrange some accommodation for him @Kerzen

No, the Samaritans are for you to talk to.

The Police should be able to help in some way, even if it means a blanket in the waiting room at the station.

Do you think he is outside?

If you do think that he is outside, it might be best if you ring the Police yourself, he will freeze.