Can I replace p6ke110a with 1N4148 in my smps circuit
Without a schematic or circuit drawing, I can only compare spec to spec and part to part.

The P6KE110A is a transient voltage supressor (TVS) diode rated at 116V breakdown, 152V clamping and 600W (peak pulse) dissipation. A 1N4148 is a general-purpose diode rated at 100V - it is not a TVS and is not intended for repetitive high-voltage breakdowns. They most certainly do not have the same specs, and as such should not be swapped.

According to ON Semi, the P6KE110A is obsolete. This is presumably why you are looking for an alternate part. Please limit your choices to TVS diodes with comparable power dissipation and clamp voltages and steer clear of general-purpose diodes for this swap.