My friend went to jail for criminal sexual abuse they gave him probation for the charge but he violated his probation and got aggravated criminal sexual abuse and went to prison well he got out and had to do 4 years parole well he violated his parole as well he ended up doing a year and a half prison time the victim was 15 and my friend was 22 years old will he be able to have joint custody of his kid

Most likely, he will be considered a felon, as well as any other felon, but this is not a sex crime that puts his child at risk, it appears it was a dating a minor issue, not a rape by force ( although this is assumed since you did not say)

But I see no issue with his own child.