• 込こむ — to be crowded; to go into
• 申もうし込こむ — to apply; to subscribe
• 割わり込こむ — to cut in; to interrupt
• 持もち込こむ — to bring in
• 引ひき込こむ — to draw in; to withdraw
• 込こめる — to put into; to load (emotion, meaning, bullets)

込 is a しんにょう kanji — all about movement. But here the nuance shifts from simply “going” to “going *into*” or “piling into.” That’s why it appears in phrases like 人込み (a crowd of people) or 申し込む (to apply, to submit). It carries the sense of something being enclosed or filled by movement.