The dose of Paracetamol is 15 mg per kg weight of the child. If possible then you can ask a chemist nearby how to do this.
You take the recent weight in Kg of your child and multiply it by 15.
Then there are two types of Crocin 120 and 240. Each signifies how many milligrams per 5 ml of liquid are present.
So if your child is 9 kg, then they need 9x15 = 135 mg. Hence its 5.5 ml of Crocin 120 and 2.8 ml of Crocin 240.
Next Steps
Get to the chemist if they don't understand how to calculate.
Health Tips
Please do not self medicate if you are not sure.