どっちを

which one

→ どっち
phrase Uncommon #17,796
which one Used when asking which of two options is the object of an action. どっち is a casual form of どちら.
JA: この二つなら、どっちを買う?
EN: Of these two, which one will you buy?

どっちを選べばいいか決められないよ。

I can't decide which one to choose.

仏語とアラビア語どっちを先にやる?

Which should I learn first, French or Arabic?

— 預言者 (2009)

ゾンビものと吸血鬼もの、どっちを観るかなあ。

Hmm, should I watch a zombie movie or a vampire movie?

選べどっちを撃ってほしい?

Choose—which one do you want me to shoot?

— シティ・オブ・ゴッド (2002)

デイジーの友達にどっちを?

Which one for Daisy’s friend?

— ラブ・アクチュアリー (2003)

どっちを選べばいいのか分かんないよ。

I don't know which one to choose.

どっちを見ても平ら

No matter which way I look, it’s flat.

— どん底作家の人生に幸あれ! (2019)