All other things being equal, available NFETs have a lower Ron than PFETs. If you are driving a load where it is optional that the common-source FET switch can be either in the high-side (PFET) or low-side (NFET), you can get a lower heat dissipation putting an NFET in the low-side. NFETs are usually cheaper, and more readily available than PFETs.
I am not getting good point of DEPLETED & ENCHAMENT Mosfet in practical Use but Understand There Construction Pls give some code number of both Mosfet as I am not getting Them in market..........!
Almost all junction-Fets are depletion mode and almost all Mosfets are enhancement-mode.
I buy them online from Digikey or Newark who have "every" electronic part.
Sometimes I buy food at a market but usually buy food at a large grocery store.