Hi there...green tea extract has been known to be beneficial in lowering blood pressure, glow of the skin through its antioxidant effects. But there are no proven studies. Even for weight loss also.
For your height, your weight is normal.
Even then if you want to lose weight, You have to follow a strict diet and exercise schedule. Regarding diet - have small multiple meals instead of 3 big meals, eat food rich in proteins and fibres like egg white boiled chicken vegetables fruits pulses, avoid carbohydrate rich foods like rice curds oily foods sweets ghee and other junk food. Regarding exercises - start slowly with brisk walking, then change over to jogging, running and other abdominal exercises. Never over strain yourself. And always keep yourself well hydrated and enjoy whatever you do. Also consult a dietician at any hospital who will be able to give you a proper chart regarding the same