If you think, eating fried food and then drinking cups of green tea will not let your weight increase or instead reduce it - You are absolutely wrong.
Green tea does have a lot of health benefits as it is loaded with antioxidants that can have positive effects on your body but it would not reduce weight without putting in any effort. This 0 calorie drink can boost your metabolism a bit and improve your body's efficiency to burn energy but it will not directly lose weight.
So stop drinking green tea just because you have eaten an extra bhatura, burger or pizza.
Drinking excess of green tea can cause problems in liver stopping it to work in order. Also excess of tannins (present in green tea) can cause insomnia (lack of sleep) and can interfere with absorption of some vital minerals and vitamins (iron etc).
So, drinking it once a day is fine but do not keep on sipping green tea assuming you would lose weight just by drinking it.