I'm not going to contact my autistic brother.
Why are you not going to contact him?
I'm not going to do this for the time being
It is wrong to cut your brother out of your life because of his autism. He is family and he needs your support. Can you imagine how hurt he might be to not talk with you?
I don't know how to deal with autistic people so I'm not going to talk to him at the moment.
If you have no idea how to interact with them I think seeing a therapist could help you work through some issues. It is unfair to him if you completely abandon him because he might not understand why.