Briefly, what are the requirements to immigrate to the land of Israel?

ב"ה Shalom To be very brief, Aliya to Eretz Yisrael is a mitzvah which is incumbent upon every Jew in every generation (רמב"ן תוספת לספר המצוות מצוות עשה ד, פתחי תשובה לאבן העזר סי' ע"ה, ס"ק ו The mitzva of living in Eretz Yisrael is tantamount to fulfilling all the Mitzvot of the Torah. (ספרי פרשת ראה, סי' פ) If you have more specific questions, on this issue, you may ask again. All the Best and Chag Same'ach