You really need to be ...

You really need to be careful. The simple answer is UF/RO and mixing the resulting stream with water that has only had UF to give the TDS you need. You do not need to RO all of it. However, you need to characterize your feed better. There is a large percentage of the TDS you have not identified. If that is Ca, Mg, Si, etc as hardness and that is at a high level in your recycle at specific periods, your dyer is not going to be happy with you. Also, that UF fraction in many countries (USA, India) may need to be treated as hazardous waste and you need to account for that cost. To remove the hardness, you need to look at NF instead of UF.