Hi dear Osama If you insist ...

Hi dear Osama

If you insist on useing these methods, then you have to go for smbs first and then heading for activated carbon. But make sure that you are using a propper ORP meter in your system first. If you have huge flow of water then the carbon filter will be out of service soon. The carbon filter can help you with the Cl leftovers. It would be great if you can use an ORP meter in the outgoing water stream to make sure about complete Cl removal. Some ORP meters can inject proper amout of smbs acording to their system. But in case of decreasing the cost and the TDS  of outgoing water you can use ozonation process along with the ORP meter (actualy you only need one), especialy if it is a RO feed water. Instead of Cl you may also choose a propper UV system, then you dont have to use smbs, Cl and ORP meter.

Stay safe.