Can I put my baby on walker, he is 7 month 8 days

Never. The american academy of pediatrics recommends against the use of infant walkers at all ages. I recommend against the use of walkers as well.
I would avoid one. Although quite popular, walkers are not a necessary part of baby equipment. As the child becomes more agressive in their scooting about, the frequency of tip overs increases along with head injuries. Tip overs happen as wheels snag carpet, cords, floring change etc.