哥俩 is a colloquial fusion meaning 'the pair of brothers/buddies'. Use with 们 for the group: 他们哥俩. The 俩 here is read liǎ — the trick-sense liǎng reading lives only inside 伎俩.
register
Casual and spoken. Carries warmth — implies real closeness, whether literal brothers or chosen-family male friends.
