I am 28 & i was 62 kg 1 yr ago when i started working in car wash i lost 6 kg during my this one year of work i wonder how can i gain weight again.?

What work? do u eat?: What kind of work are you doing-cashier (sedentary) or cleaning (active, physical)/ have you changed diet? If you are more active than before, but didn't increase intake to keep up with the calories spent-you'll lose weight. Feeling otherwise well? Just to make sure nothing else is going on, overactive thyroid for example, see your doc.

Eat and rest: Dedicate specific times to eat peacefully and give your body proper rest. Sometimes its a matter of fast metabolism... Avoid stressful lifestile and you should gain back some strength.

Gaining weight: While most of us need to lose weight, gaining weight can be just as hard. However it is possible to do it healthy and quickly. Eat often and eat lots of protein and carbohydrates.Eat healthy fats and eat late like peanuts, cashews, and olive oil. More weight training then cardio is recommended to gain muscles. Regular physical with your pcp is also important.