have many (or other) irons in the fire have many (or a range of) options or courses of action available or be involved in many activities or commitments at the same time.

☞ Various tools and implements made (or formerly made) of iron are called irons, for example grappling irons or branding irons. The metaphor is of a blacksmith or other worker who heats iron objects in a fire until they reach the critical temperature at which they can be shaped or used.