Where Frodo on the evening when Pippin and Beregond walk on the walls of the citadel of Mias Tirith?

On the evening when Pippin and Beregond walk on the walls of Minas Tirith, Frodo is in the citadel, recovering from his recent experiences and the burden of the One Ring. He is likely resting and reflecting on the events that have transpired, as the city prepares for the impending conflict against Sauron's forces. Frodo is also supported by Gandalf and the others, as they strategize for the battles ahead.