Each has their pros and cons:
2.4 Ghz
- Generally better range than 5 GHz.
- More interference with other networks (which can lower range).
- Lower speeds.
5 GHz
- This is essentially a higher bandwidth version of 2.4 GHz WiFi.
- It has shorter range and can have more interference with walls and physical objects.
- However, in most cases, it is faster and has less interference with other wireless signals and electronic devices.
Depends on situation:
For 2.4 GHz
- If you want to use wi-fi in long range
- If your LAN connection is slow
- Not a gamer or streamer
For 5 GHz
- If your gamer or streamer (recommend to use 5GHz)
- Speed lover(internet speed)
- LAN connection is fast (more than 500 MBps)
- When your router is not too far like you are in home
source:Quora