My daughter is 6 years old. She is crazy for cartoons and mobile games

There should be time assigned for gadgets and you have to strictly enforce timings. Too much time on gadgets also hamper brain development when children are young. So try to get her involved in some physical activities, like going to the park to play with other kids. Try to spend some time with her and do arts/craft work together. And you have to contribute too but laying off your gadgets when she's around as kids tend to pick up habits more from their parents than anyone else!