maximum collector-emitter voltage in BJTs
when you are biased the transistor may be particaly open
you can calculate depends on the biasing the Vce voltage using simple DC analysis:
first you need to know the base current can be calculated by KCL
then collector current can be calculated by Ic=hfe*Ib
and the emmiter current is Ie=Ic+Ib
so now just substruct the main brunch voltages to get Vce

here is a great example for DC analysis
https://www.allaboutcircuits.com/textbook/semiconductors/chpt-4/biasing-calculations/