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

Is suppose, you meant to seek a suggestion as how to put her off gadgets. I think you must set a time for her when she can watch cartoons. And personally, I would not allow my child to use mobile for playing games. If you will not tap her behaviour or demands now, she will become more and more stubborn in future. So, I think, you must set time for her to watch cartoons and at other times, take out the plug of television or can make an excuse that it is not working or whatever work for you. And for mobile, you can put lock on it so that she can not open it. She may throw tantrums for a first few days, so let her do that and eventually she will understand that mamma will not budge and she has to follow her timings.