Hi Sanuj,
We can all endorse our own materials, but the most important thing is that you work with a set of strategy guides that will enable you to fill in the holes in your performance, and perhaps improve your overall confidence and time management. I would strongly advise against making full tests the focus of your study. You need to make sure that you have a firm grasp of all the basic content, and that you have a useful strategy (or better yet, several useful strategies) for every problem type. You won't get this from simply taking CAT exams or working through the
OG. I'd recommend that you spend a few weeks studying and doing practice problems before you attempt any more CATs. Then take them about once a week (or less often, if you decide to retake later than October). Make sure that you don't take a new CAT until you have thoroughly studied the last one. What are you doing well? What isn't working? What are you going to do differently next time?
Specifically, it looks like you need help in verbal. Our Sentence Correction guide is probably the most comprehensive resource available for that topic. Give yourself some time to work through it, but keep your work balanced. You don't want to get one skill far ahead of the others. For instance, if you get really good at SC, the test will give you really hard CR & RC, and that won't go well if you haven't also practiced those topics extensively.
Good luck!