Need to add skill to my app to change it from 'game to chance' to 'game of skills'

Hi, Hello, I have created an Android App that organises online contest after every one hour or less than that in which e.g, every contest has 50 spots and about 25 or more winners. Users have to pay entry fee and when then contest period is over (contest countdown), the system automatically declare the winners. I came to know that this type of game (game of chance) is illegal in India. Now I want to add some little bit skill to it so that becomes legal as 'game of skills'. Freelancer should add changes to backend admin panel (php) also. NOTE: I have no idea of what skills need to add, you have to give idea of that