Height increase methods for 21 year old

Patient: I am 21 years old and my height is 162 cm and i want to know if there is any chance to increase my height 3 cms, i want to join the police and 165 is the minimum height required, i have heard about an operation in the legs. is it very costly and how many months or years of rest is needed and also will i be able to do all the physical activities i have done before the operation if that is not a good option pls tell me about the change in posture i need to do and also the diet and excercises i need to follow for height growth, thank u