Hi Srijan

That is certainly a good score in Mains. If you know the concepts well enough, and only lack in practice with respect to Advanced questions, you would not have much of a problem as long as you are putting in 9-10 hours everyday, studying for Advanced. Solving past year papers is a good practice, it really tells you which chapters you need to focus on. I have a little advice for you, when you solve past year papers, spend an hour or two later analysing it. Look where you went wrong, is this a type of mistake you often make or is it particular to a chapter. Make sure the kind of mistakes you are making in one exam, you don't make in the other. Careless mistakes can always be avoided, conceptual cannot. However, once you know which concepts/chapters are not very clear to you, you can focus more on them. Since time is limited now, you will have to make  atrade off between chapters. You can avoid/give less time to seldomly asked chapters in Advanced. The questions in advanced are often a combination of many concepts in one, unlike in mains. That is precisely the only difference. Applying several concepts at once can only come with practice. And if you do it sincerely, you can ace Advanced! All the best!