Welcome to HCM,
Please take care of your health it is good that you are aware of being overweight
, your height is 168 so your weight should be between 55 to 70kg maximum.that is BMI 19 to 25.
See weight depends on genetics and intake of calories and burning of calories daily as there is daily calories requirement for metabolism
If you do lot of physical activity additional calories are required,in sedentary lifestyle 30Kcal/kgbody weight are required in your case 2400 Kcal/day.
If you want to lose weight reduce calories intake by 500Kcal and increase physical activity by 500 Kcal so as to create negative balance.
In diet take breakfast,lunch and dinner avoid fatty,and sweets,fast food like pizza,Burger,Chocolates,coffee,Tea in excess.Take help of Dietitian
It takes long time and determination to lose weight,I am sure if you follow simple rules you will lose in few months as at younger it is easy to reduce.
Keep good nutritious diet with fresh fruits and green vegetables may be in form of Juices without sugar.
Best of Luck