Dear Niket,
[Office Order]: Issued by the competent authority, an office order contains instructions related to office work, changes in working hours, instructions on closed holidays, messages by senior authorities when they take over an organization, promotions, etc. Office orders are issued periodically, such as every Monday or on the first of the month. The sequence of the information is pre-decided.
[Circular]: An advertisement, usually printed on a page or in a leaflet, intended for wide distribution. It need not be issued by the competent authority, but generally, it is issued by officers or managers. Circulars are for a specific purpose or event, like a meeting or any other event.
[Notice]: A sign posted in a public place as an advertisement. When government authorities issue some communication, it is also called a notice, for example, a notice by a labor officer.
Dinesh V Divekar