You must absolutely patient with your expected progress in the VA-RC section. This is one section that can't be improved in a hurry. You have to give it time and attention. Don't lose your cool if you have to spend lots of time on VA-RC problems and still get them wrong. Frustration is like the antithesis to achieving accuracy. The more frustrated you are, the worse your performance will be.
Know that while there are some areas in VA that you can improve upon with practice, others require a degree of functional knowledge that can only be gained by reading. Especially when it comes to reading comprehension questions or RCs, you have to be mindful of the different difficulty levels.
When it comes to overall strategy for the VA-RC section, if you want to miaximise your accuracy, you need to be selective about which RC questions you answer. For this you need to skim through the various questions quickly and make a decision as to which ones' you'd be prioritising. In such a case, a reading habit basically helps you immensely.
So at the end of the day, work on developing those reading chops overtime. You can start by selecting a subject that interests you - music, psychology, sports, food, fashion, fiction, etc. Just pick up books, and blogs on one of these subject and start reading!
You'll end up developing stamina to pace yourself, the speed to read long pieces of text in a short time, as well as the ability to comprehend or understand what you're reading. Even if this prep strategy pushes you out of your comfort zone, it'll be worth it. Maybe sometime into our new reading, you can start looking at topics which you find difficult or tough.
For example, suppose you are really good at psychology passages, average at science and general texts and terrible at math or physics related stuff. After reading about your topic of interest, you can move to psychology, and improve your scores in those areas. Then move to science and after some time, to math and physics related works. You can also read magazine to get used to the whole process. Don't forget to stay on top of those editorials we pointed out in Step 1 though!
When it comes to mastering grammar for CAT, apart from reading and understanding sentence structures, formations and vocabulary, you can also refer to Wren & Martin or the Oxford Dictionary. There also various apps meant to help you with vocabulary. Look at wordlists to make sure you're prepared.