How soon after a Breast Reduction can you swim or sit in a bath?

No, 6 months is much too long of a period.  Generally speaking, patients are able to return to these types of activities once incisions ( 4 to 6 weeks for most patients) have completely healed.  Your plastic surgeon, following you clinically, will be your best resource when it comes to returning to all types of activities. Best wishes for an outcome that you will be very pleased with.

I ask that all my breast reduction patients refrain from getting the wounds wet for three days post op. After that, showering is encouraged but patients are asked not to soak in a tub until all of their incisions are healed over. This may take up to two weeks. Strenuous activity however should be avoided for up to six weeks following breast reduction surgery. 

After surgery, I generally tell patients to avoid standing water for approximately 4 weeks. River water and standing water can have bacteria and other contaminants that can cause infection in the surrounding tissue. The timing can vary and is surgeon practice dependent so it is important to clear your particular case with your surgeon.