How do I get rid of my 6 month old baby's congestion problem?

Check environment. Babies have a certain amount of secretions and mucus, it helps lubricate the airway. The issue is is it a normal amount or not and whether the baby is bothered by it or not. If you think it is not normal, consult your doc and check your home for indoor pollutants and possible chemicals that may release fumes, such as air fresheners and certain cleaning products. Also check baby´s diet.