Answer:
Jack is most likely going to join a retreatist gang.
Explanation:
First of all, let's explain what a retreat gang is and then figure out why he is going to joint it.
A retreatist gang is a gang product of the retreatism subculture, which is characterized by the seek to be constantly high. This type of gang originated after the association of young criminals who failed in the criminal subcultures. They retreat to drugs, alcohol abuse and duel between a double failure in the first moment to society and the second to join a criminal organization.
Now, the reasons that will make Jack join a retreatist gang are that in the first he practices drug abuse. The second is that he experienced fighting and he failed. So after trying a more violent gang and have failed he will retreat to drugs and look for a gang with members like him.