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It depends a lot as they said from the number of layers that you have, connections, ball pitch and other factors. I suggest to use the automatic function by Altium first to see if it works. You have to define first the pcb rules otherwise it will not work at all or it will produce wrong results. When you have defined your rules then you can go to the desired component in Layout right click->components actions->fanout component. Depending on the package you might have to use a high class PCB (more expensive) in order for the fanout to be successful.
There isn't a single fanout topology for generic BGAs because the fanout will strongly depend on the function of the pins. For example, ground pins should be fanned directly to the ground plane, power pins should be fanned to a decoupling capacitor on the back side of the PCB etc. For small BGAs such as a 10 x 10 the best electrical result is probably achieved by fanning out manually.