Good day guys! What is the difference between PMOS current mirror and NMOS current mirror? What are their advantages towards each other? Thank you for your response...

I think for the same device length there will be difference in resistance seen from drain for PMOS and NMOS. This means your Vds variations between mirror transistors will introduce current mismatch. What you would want to do is just take one PMOS and one NMOS and make a sim of Id vs Vds. The one which has more flat characteristic in the saturation area (and for the same Vgs) will make a better current mirror.

EDIT: That and PMOS will require more overdrive to provide the same current - lower hole mobility.