I totally agree with Hairo! However, it's also very often used colloquially (among young people above all) with the meaning of 'like'. Sometimes it's used as a pet phrase. "Y yo estaba en plan '¡no puedo creer que me haya hecho eso!'" - "And I was like 'I cant believe he did that to me!'" "Es un jardín precioso. En plan... Con muchas flores, una fuente..." - "It's a beautiful garden. Like... With lots of flowers, a fountain..." It's difficult to explain! :) I hope it helps!

Ayudaria agregar una oracion completa, pero quiza te refeiras su uso en oraciones como: "El está en plan de reconciliación" o "El está en plan de conquista", en esos casos se podria replazar el "está en plan de" por "tiene la intención de" como "El tiene la intención de reconciliación". In English, these two colloquial examples would mean something like: "He's in reconciliation mode" and "He's in flirting mode" respectively.

Hi, I think that it depends to the country where you are. In Latin America people give different meanings to the same phrase. But the explanation given by Hairo make sense. I can add a colloquial some meanings based on the usage of this phrase in my country. * "En plan" could have positive and negative connotations, for example: - Mi primo esta en plan de ahorro (My cousin is saving money) express a positive action. - Ella esta en plan de actriz de cine. (She is acting as a movie actress) can have a negative connotation if it means that the woman is too arrogant. Hope this helps!