My 6 month old has a blocked airway what should i give her ?

Nasal congestion: Assuming when you say blocked airway you mean her nose? The simplest and most effective thing you can do for your baby is to use saline nose drops (salt water). A drop in each side of the nose then using a baby suction bulb, suck out each side of the nose in attempts to relieve the obstruction. I recommend doing that at least before each feeding and prior to bedtime.

Blocked airway.: This depends on what part of the airway is blocked. If it is her nose, then normal saline nose drops and prop her up. If it is further down the airway, take her to her pediatrician. She will need to be seen if she has strider or is wheezing. I hope this helps.