Hi i have a six month old baby, she sleeping good but mornings she does not sleep on back she sleeps only on stomach(not on bed) how can we adopt her sleeping on her back?

I always put them down on their back to start with. That has been the recommendation since the early 90's Back to Sleep campaign that successfully dropped the crib death rate about 40%. (but not all) Once they have the physical ability to turn over and assume a position of comfort there is less worry. Crib Death peaks at 2-4 months. I would not wake a sleeping kid at 6 m to reposition them.