My evaporator coil will only get ice cold on the lower portion and the upper half is warm .
What would cause this problem, possible restriction?

The point where the evap changes temperature may be where liquid is "boiling" into vapor. If such is the case, the system may be "flooded". Liquid should be changing to vapor at the expansion valve, not half-way in the evaporator.

Can it be low on charge.

Low charge is certainly a possibility. So is a restriction. It's possible one or more of the distributor tubes are blocked in some way.