I think that active reading (writing the main point of every paragraph) is decreasing my accuracy rate. what should I do? should I give it more time to practice?

Do not go by any arbitrary rules. The trick that increases someone's accuracy rate might decrease yours. I also tried writing the main points while solving RCs but that trick never worked and helped. So, I would say try using different tricks and use each one with a couple of RCs and see what works well for you and stick to it. And trust me you will find that one particular trick that will work the best for you.

Try doing it for 20-30 rc you will see good results and later on, your brain will structure all rc in the same manner which means you won't have to write main points every time

How much time to spend per RC in CAT mocks? Because the daily targets are usually timed for 15 mins, getting an idea of how much time one should actually take to solve an RC is something I'm facing difficulty in.

Hi Anirudh, the RC strategy varies from person to person - it largely depends on one's proficiency. Ideally, 8-10 minutes is suggested, but this could vary depending on the RC difficulty. The Daily Target RCs are mainly to help aspirants improve their comprehension - for more targeted practice (or to devise test-taking strategies), mock tests and sectionals are ideal.