C3H6O did not give a silver mirror with Tollen's reagent but gave an oxime with hydroxylamine. It can give positive: Fehling's test, Iodoform test, Carbylamine test, Schiff's test

Since it gave an oxime with hydroxylamine it is either a ketone or an aldehyde and it didn't give silver mirror with tollen's reagent so it is ketone. According to the given molecular formula, its structure is CH3−CO−CH3 and It can give positive iodoform test.