Thank you for your query.
of 6 is something to be worried of for a 6 month old baby and moresoever when he is passing reddish stool. He needs to be worked up so as to find the cause of:
1. Reddish stool - is it blood loss in the stool?
2. Low hemoglobing - it could be attributed to the blood loss in stool
I suggest that you consult your doctor and, if required, consult a pediatric gastroenterologist.
I hope I have answered your query to your satisfaction.
Wishing your baby all the best...