Can a inline 6 fit in jeep liberty?

No, an inline-6 engine will not fit in a Jeep Liberty without significant and likely impractical modifications. The Liberty's engine bay is relatively small and designed for V6 engines. An inline-6, even a relatively compact one, would be too long and likely interfere with other components like the firewall, steering column, or suspension. The required modifications would be extensive and likely not cost-effective.