What is the permissible TDS in water that is to be used for drinking purposes for infants?


I am Praveen from Chennai (11km from coastal region) I have a 2 month old baby.

The TDS level of borewater was 1250ppm, so we deployed a RO plant for my apartment of 108 houses. The output of RO plant is 125ppm.

Please advise if I can use this water with some UV filter for my baby. Let me know whether I need to test the RO output for any essential minerals? Do I have to test if it still has harmful content like lead, mercury, nitrate ,etc ?

Thanks in advance

- Praveen Kumar