It's pretty simple masi - you need to lose (21.1kg - 18.7 = ) 2.4 kg of fat. Easist way to is to start putting some muscle on. Lift weights, start strength exercise regime. Yoga really helps too. Cardio 30 min 3 X week.
I don't know how accurate these machines are. I know they use to to these tests in water to caluclate the exact amount of fat vs. muscle ratio but it's maybe based on a formula.
i am not sure but based on your BMI and your fat weight i say you are about 157cm tall and weigh about 62Kg's which is slightly over ideal weight/height chart (you should be under 60Kg or at 60) but this is not the concern. your 1/3rd of weight is just fat which is not good.
Any BMI(body mass index) over 25 is considered fat but it is debatable in fitness professional people coz lets say you have fat percentage of 17% instead of 34%. in that case your BMI would still be the same but you would have the fat weight of just 10.x kg's and would have pure lean muscle of 51Kg's so in future having this much muscle you wont look fat even if you gain more weight than your current like upto 65 or 68 you wont look fat coz of the added muscle mass.
back on topic, fat loss is all about calorie in calorie out formula, its very simple.
again just assuming that your are 62Kg's and about 5feet 2inch tall and your age is 35 i would say your caloric maintainable level is around 1800. if you age more caloric level be less and vice versa. in order to loose fat you need to consume less than 1800. if you exercise 3x a week than i say you shouldn't go over 1500 calories (and dont be greedy and go under 1200 calories in order to fast fat loss, you gonna end up loosing your muscle mass). its very simple you just need to be consistent.
NJ, It was one of those machines at medic stores you put coins in to get weighed, so not sure how accurate that was.
Umar you are so chalaak.. but still you got somethings wrong specially my age gone.. but thanks for a detailed reply..I must admit it’s been a while since I stopped calculating calories and haven’t been working out much. I just eyeball what I eat and have cut out wheat and rice since 2 months (lost 6kg) but I know I need to do more physically, still pushing myself in that direction.
then your ideally fat loss caloric intake would be 1550. if you exercise at home. buy little dumbbell and add some muscles. it would really help you in future (very helpful to drop baby weight).
trust me, you are gonna have to do alot of training in order to make your arms show like they have muscles in them, alot of training.
The muscles i am talking about are beneath skin muscles, they are almost unnoticeable (like the bollywood actresses have, they workout for hours/weeks/months, but you dont see any muscles) more muscles you have, its tough for you to get fat and its easy for to fat loss in future.
you are so chalaak.. but still you got somethings wrong 
specially my age 
gone.. but thanks for a detailed reply..I must admit it’s been a while since I stopped calculating calories and haven’t been working out much. I just eyeball what I eat and have cut out wheat and rice since 2 months (lost 6kg) but I know I need to do more physically, still pushing myself in that direction.