My 6 months old son started to have wet cough and runny nose. i tried the nasal saline but it doesn't help much. is there anything else i can give him?

Possible infection: In this age group, runny nose and cough are usually due to infection. Most commonly a viral infection but if symptoms have been present for more than two weeks without improvement, could be a bacterial sinus infection.

Limited options: For infants, there are few medication options to deal with the common cold. Since infants need to breathe through their nose, the nasal saline is a good idea and using it with a bulb syringe (nasal aspirator) will help evacuate the mucus. Previously used cough and cold medications had more risks than benefits. If this were allergies, consider zyrtec syrup and if he improves, see allergist.