There are people who perceive that children are having much more leisure hours as a whole in general and insisting to use those times to do work related to their studies.
.... try to present the core idea without lengthening the sentence. It helps improve the clarity. Here your idea is to say that some believe children should spend their leisure time doing school work. Say it direct;
There are people who perceive that children should engage in activities that are related to school work during their leisure time.
You should have a strong and clear sentence for the opening line. You can take lots of help from the prompt, though you should not repeat it one to one. But there's no harm in taking its sense.
. I agree with the view, it is however, the leisure hours can spend in a different ways, so that children able to realize their social responsibility and hidden potential.
This is good, but reader tend to find out what these different ways are. So you need to tell the reader about them.
Besides, academic curriculum, students should be encouraged to participate inbuilding activities which will help them to understand the significance of unity.
....it should be "personality building"
You need to give a specific example for this reason. Talk about some program that helps them learn such life skills. Remember, it's important to give specific examples.
You write well :) Have confidence and do it. Remember your structure well and stick to that!
Good Luck!
