Why would the doctor prescribed albuterol for cough, and prednisolone for cough also for a 6 years old kid?

Sign of bronchospasm: A cough can be a sign of bronchospasm or an "asthma-like" response to a cold or an allergen. Therefore we treat it like asthma with an albuterol and steroids. The cough is usually drawn out and with coughing spasms and worse late at night.

RAD?: If they examined your child and/or know their previous medical history and problems, etc, they could possibly be treating a condition such as reactive airway disease, which can do well with those medications. Ask the Rx doctor to get the real answer. Best wishes.

Asthma: Hi. Both of those drugs treat asthma, and cough is a common manifestation of asthma, so putting two and two together, I'd come up with the suspicion the pediatrician suspects asthma as the cause of the cough and is treating accordingly.

I agree. Those meds : treat the bronchospasm & inflammation of an exacerbation of asthma, aka reactive airway disease. Ask his pediatrician about long-term management; i.e., use of maintenance medications, when to start bronchodilators in future coughing episodes & evaluation for triggers of his asthma by a pediatric allergist/immunologist. See http://www.health.ri.gov/asthma/for/parents/

Asthma: The doctor prescribed these medications because the child was wheezing.