Hello dr, I am 30 yrs old my weight is 65 kg but my breast is too big how can I reduce my breast size immediately?

There is. No "immediate" fix for this. You didn't mention your height so it is difficult to determine if losing weight would aid this, but that would only aid you to a slight degree. Your best and most reliable choice for a cosmetically good result would be to contact a good plastics/reconstructive surgeon.