Hi @Teja114
I hope you are doing well!
Our SDK examples use the external clock for MSCAN and also this clock is used for generating other clocks, See ICS FEE (FFL Engage external mode) in the KE06 Reference manual Chapter 20 Internal Clock Source (ICS). Yet I do not have an example with the required configuration to provide you.
For clocking the MSCAN with the internal clock (internal oscillator) you may try to use the Bus clock (MSCAN supports two clock sources). For example, the bus clock can be generated by the FLL, and the clock source for the FLL can be the internal clock.
However, and external clock will provide more accuracy and will have less jitter than the internal clock. I would recommend checking if with the internal oscillator you can meet CAN clocking requirements for your desired can bus speed. More detail regarding MSCAN clocking in the reference manual chapter 32.4.5.2 Clock system.
As a little commercial, if it helps for your development, you can try the MCUxpresso Config tools. I like to use it because it gives me a graphical overview of clock trees and lets me generate initialization code. Below and snapshot of the KE06Z clock diagram, with the ICS in FEE mode in the Config Tools Clocks tool.

My apologies for the delay,
I hope this could help you.
Diego.