By Rabbi Chaim Chazzan
One who is only ready to light the menorah after the time of maariv has begun (i.e. tzei hakochavim – nightfall) and has no minyad readily available: should he wait to daven maariv with a minyan and light later, daven maariv without a minyan and light, or should he light before maariv and daven with a minyan later?
It is minhag Chabad to light the menorah immediately after shkiah between Mincha and maariv. However, if for whatever reason, one did not light before maariv time, he should first daven maariv and then light the menorah.
This is based on the principle “tadir vesheino tadir todir kodem” – when faced with two mitzvos, one should fulfill the one practiced more frequently first. In addition, when davening maariv, one fulfills the mitzvah mide’oraisa of reciting krias shema, which takes precedence (according to some) over lighting the menorah which is miderabonon.
However, one only should daven maariv before lighting if he can do so with a minyan. If there will only be a minyan later, or he is currently unable to leave his home to go to a minyan, he may first light the menorah and daven maariv later.
The reason for this: The principle of “tadir vesheino tadir todir kodem” only applies when one is ready and able to fulfill both mitzvos immediately, in which case, he is required to do the more frequent mitzvah first. However, in a situation where (for whatever reason) he is not about to fulfill the more common mitzvah, he need not wait and should fulfill the mitzvah for which he is ready.