Hi,

If you try to cover those 3 chapters that you couldn't study now, you will  have trouble with the chapters that are being taught currently. My advice is fhat you should focus on the chapters that are being taught now. If you have free time, try to cover the chapters that you couldn't study. The institute itself will run revision classes later so you could just join them later and study those chapters.  Moreover aince you're in class 11th, you'll get a lot of time when your session ends. So for now you can try to get basic knowledge of those chpapters and then later study them in depth.