How to cook rice with fish without overcooking the fish
While boiling/cooking rice and fish is safe for consumption, the cooking method gives the rice an extremely fishy taste. If you crave that flavour, go ahead with cooking the two things together.

However, if you wish to retain the individual flavours of the food, par boil the rice while you can pan fry the fish pieces in a separate utensil (to get rid of the excessive sweet/salty fishy flavour). Add the fish to the rice at a later stage. By doing this, not only will the fish pieces retain their shape and form after frying, but your rice would remain fragrant on its own as well.