Is it ok to use CamelCase naming convention in C code base?

If you think it looks pretty, and it's your code base, then yes.

If it's an existing code base and you're not the sole owner, discuss it with the others.

No, it is not.

It depends you, my choice is camel case

OK with who? No one will force you to use any particular style.

By convention C programmers usually use underscores (snake case). Conventions and idioms have some value -- other programmers can more easily read and understand code when they don't have to translate idiosyncratic style to what they're used to.