Meritation is the biggest name in the educational websites of India, and it definitely deserves this.
Meritnation has the course content of almost every course, they also provide online coaching and mock tests of the competition exams.
Meritnation also provide the solutions of the all the major books and ncert books of all the classes, but, I have also seen students who are misusing this by copying their homework from meritnation, and I am also one of them.