I am 21 year old female. My height is 5'2 ft. How can I increase height by exercise?

Can not. Unfortunately, you cannot increase your height by exercising.
Unlikely to happen. Some kids continue to grow taller into their late teens or rarely early twenties but only when their bone maturity lags behind their age. If the growth centers of the long bones have fused, you cannot grow taller. A single x-ray of the wrist/hand can yield a bone maturity. When your maturity reaches 18-19, your growth centers have fused and you are done.No meds or exercises can change that.