post delivery, I have become fat like football, will anyone tell that from when I can start doing exercise?

A. If it was a c section u could consult with ur gyneacologist after 6 months to ensure if the stitches have healed and then start with mild exercises which doesnt involve weight lifting and gradually move on to heavier ones. For now u can do walking. Yoga like bhujangasana, surya namaskar, pawan mukthasana can all help.