Can I administer Orapred (3 ml 2/day) along with breathing treatments (Budesonide or Albuterol)? Baby had croup but now cough sounds rattly.

Croupy baby. A baby who has been prescribed steroids, inhaled steroids and a bronchodilator, whose cough is worse, needs to be seen and evaluated by his/her doctor. At the very least you need to speak with the doctor about your child's deteriorating condition.
Maybe/not. This should only be done in consultation with the babies doc. These oral steroids can mute the bodies natural immune response and interfere with the effectiveness of immunizations. Timing is important.There is a reason it is a prescription medication.Anything strong enough to do good is strong enough to create problems.