Hi Rekha, I did start my baby on wheat bread when around 10 months of age and it was absolutely fine. In fact, whole wheat bread is a great source of energy and carbohydrates and is perfect for busy babies and growing toddlers. Whole wheat bread also gets digested easily, which means your baby will not have any stool troubles. You can check with your baby's doctor to know how much quantity you can safely give. One thing you should keep in mind is that whole wheat bread can aggravate asthma symptoms. So, if your baby suffers from the same, you may have to limit the amount of whole wheat bread your baby has.
If your baby is ok, why not, i start straight with brown rice and wholemeal bread, they taking well and digesting well. The only concern is scare they will constipate hence need to let them having enough fluids to help with digestion. Or fruits like prunes etc too.