I have this 2 MCUone works with 3.3V and the other with 5V and I want to send a signal from the 5V MCU to the 3.3V MCU, what can I do with out burning the 3.3V MCU?
You don't need a divider, a 10K resistor from U2 to the base will work fine.
If there is no pullup in U1 then connect a 10k resistor from the collector to 3v3 and connect the pic pin to the collector.
If you want to use a divider then connect the middle point of the divider directly to the pic