What is the TDS of water provided by Noida authority?

How to reduce the TDS in water?

My family is living in Noida since 1985. We are using RO filteration, but recently three ROs have stopped working. AMC vendor says authority water has high TDS of 2500 on first floor and 3500 on second. I want to know if RO does not work when TDS is more than 2000. I have installed new pipes. Please suggest, how to reduce TDS in water?