Definitely not. Pacific Rim has no connection to manga. It was conceived and brought to life specifically as a cinematic production with its own distinct storyline and universe.
It's a story of humans fighting against giant monsters from another dimension using huge robots. The robots are piloted by pairs of humans who need to have a mental connection to operate them effectively.
Most likely not all 'Pacific Rim novels' are suitable for all ages. Since the concept involves giant monsters and intense battles, some novels might have scenes of violence and destruction that could be too intense for younger readers.
There could be 'Pacific Rim' novels that focus on the Kaiju themselves. They might explore their origins, how they evolved, and what their purpose is in the context of the story. Maybe they are creations of some otherworldly force for a specific reason that the novels can delve into.