aliyah vs in-migration

aliyah and in-migration both are nouns.

Word	Noun	Adjective	Verb	Adverb
aliyah	Yes	No	No	No
in-migration	Yes	No	No	No

As nouns, in-migration is a hypernym of aliyah; that is, in-migration is a word with a broader meaning than aliyah:

aliyah: (Judaism) immigration of Jews to Israel
in-migration: migration into a place (especially migration to a country of which you are not a native in order to settle there)

Other hypernyms of aliyah include immigration.

aliyah (noun)	in-migration (noun)
(Judaism) immigration of Jews to Israel	migration into a place (especially migration to a country of which you are not a native in order to settle there)
(Judaism) the honor of being called up to the reading desk in the synagogue to read from the Torah