If a person can stay in galut and help to make kiruv, what should he do stay in chutz laaretz (an maybe that mean he will stay in galut) or he should go to Israel. are there certain people that are meant to stay in chutz laaretz? How can be teached this desition to people?
This is a question that can not be properly answered by someone who does not know you and the situation in depth. The rule is, that when two Mitzvot clash, if one can be done by others and the other you have to perform yourself, the later takes precedent; i.e. make Aliya and the Kiruv will be other people's responsibility. You should genuinely check if your case is different.