What is max Vce for a transistor with Ic of 50 mA and without exceeding PD(max) of 1.2 W
What is max Vce for a transistor


Max Vce has nothing to do with the current you may be drawing thru the collector - it's a limit imposed by the manufacturer of the part irrespective of current flow.

Any transistor conducting 50mA thru the collector may indeed be dissipating 1.2 watts but that tells you nothing about the voltage waveform.