Splices of reinforcement in SMRF must be located/placed outside intended yielding regions. For columns, these locations must be outside the critical region, lo (I'm using ACI 318-21).
Top reinforcement in beam is lapped at mid span as the beam does not experience any negative moment at midspan and so lapping is great in that region. In case of bottom reinforcement it is lapped near the ends and again the same concept applies as there will be no positive moment at the ends of the beam.