Question: If one comes late to shul on Friday night, can they still daven Mincha?
Answer: The Mishna (Berachos 26a) writes that one can daven Mincha until evening. There is a machlokes among the rishonim as to when this is. While Mincha corresponds to the afternoon korban tamid, there is a machlokes as to whether its blood had to be offered up by shekia, sunset, or tzeit hakochavim, nightfall.
Chassidim (and many sefardim) typically follow the Rema (OC 233:1) who writes that one can daven Mincha until tzeit (See Shaagas Aryeh 17; Yechave Daas 5:22). Others, however, typically follow the Gra (OC 261:2), Aruch Hashulchan (OC 223:9), Mishna Berura (233:14) and R’ Moshe Feinstein (Igros Moshe OC 1:24) who write that one must daven before shekia and it would be better to daven alone before shekia rather than daven with a minyan after shekia.
Rabbenu Yona (Berachos 18b) writes that one must be consistent and follow one opinion rather than change whenever one wants.
The Mishna Berura (233:14; Shaar Hatziyun) writes that if one who usually davens Mincha before shekia hadn’t yet davened, they may daven up until about 15 minutes before tzeit.
The Shulchan Aruch (OC 263:15) writes that if one had already been mekabel Shabbos, it is too late to daven Mincha, and one would have to repeat the Maariv amida (tashlumin). The Mishna Berura (263:63) writes that if one came late to a shul which had already been mekabel Shabbos, they should leave the shul to daven Mincha providing it isn’t too late.R’ Yehoshua Neuwirth (Shemiras Shabbos Kehilchasa 46:5) stresses the importance of davening Mincha before shekia before Shabbos so that they can properly be mekabel Shabbos in good time.