We report the pressure (P)-temperature (T) phase diagram of antiferromagnetism and superconductivity in CeRhIn5 and CeIn3 revealed by the In-115 nuclear-spin-lattice-relaxation (T-1) measurement. In the itinerant magnet CeRhIn5, we found that the Neel temperature T-N is reduced at P greater than or equal to 1.23 GPa with an emergent pseudogap behavior. In CeIn3, the localized magnetic character is robust against the application of pressure up to Psimilar to1.9 GPa, beyond which the system evolves into an itinerant regime in which the resistive superconducting phase emerges. We discuss the relationship between the phase diagram and the magnetic fluctuations.