If i am not wrong a qbit can have any value from 0 to 1 at any given time , But if you are moving some data from a register to another in a quantum computer how will we know what state will be transferred , to the register ?
The no-cloning theorem says it's not possible to copy quantum states (pure or mixed). If you want a copy, you have to measure the qubits, collapsing them to classical information, and then copying that - but you loose almost all the information encoded in the system and you're left with normal 0's and 1's.
However, it is possible to transfer a state using quantum teleportation - it destroys the original quantum state and re-creates it in another qubit using a classical information channel and a shared Bell state. But it is not exactly clear how this can be useful in a single processor as you could just use register renaming to the same effect (with a classical computer controlling the quantum processor, you can just tell it to start calling a certain physical qubit by some other name and achieve the same result).