I am 168 CM and about 60 kg I eat about 1000 calories but I knew it is too low, so how can I increase it to 1200 calories or more without gaining?

Excercise. 5'5" and about 130 lbs... 1000 calories is low. Have your metabolism evaluated by an md. If one wants to increase calories, but not gain weight, usually exercise will keep it under control. This answer is no substitute for a complete physical exam by an md.