Normal MMR and ranked MMR are different from each other. And ranked solo and flex MMR are different from each other as well
Is ranked MMR same as normal?
They are separate. You can have high normals MMR with low ranked MMR, and vice versa. Its rare for them to be the same.
Is ranked MMR based on normal MMR?
Does ranked MMR affect normal games, TFT, or flex MMR? The answer is no, each game mode has its separate MMR calculator and is not interlinked with each other.
Is there normal MMR?
Fun fact, normal games have a Hidden MMR system so you can still get placed with similar skill people if you play it enough.