All the chapters are important for JEE Exam. You must understand the basics of all the chapters. Because no one knows, from which chapters, easy questions can come.

Having said that, having the basics clear of all the chapters, I can outline some chapters which are easy to attend in the exam : 

(1) Co-ordinate Geometry : Straight line, pair of straight line, circle, parabola, ellipse , hyperbola.

(2) Vector and Three Dimensional Geometry : 

(Both of these units are easy to crack because you can visualise their questions easily in the exam.)

(3) Statistics : One question every year, easy one.

(4) Trigonometry : Used in all the chapters. Atleast keep the basic formulas in mind. With good luck, you may be able to crack.

(5) Calculus : Very huge content to cover, as well as highly scoring. Also useful in Board exam. Keep the basics clear, you will be able to crack 50% questions in the exam. Differential equation is easy. And differential calculus is easy as compared to integral calculus.

Keep algebra chapters on the last priority. But basics should be clear of all the chapters.

About the motivation !

Question is not about how to stay motivated. Every is motivated in these times. Every decent student wants to score nicely.

Question is how stay organised ! Because in these times, we feel, ye bhi bacha h, vo bhi bacha h. And due to that we are unable to focus on one task.

This happened with me. I was trying to study one chapter, then suddenly I realised, I have to study so many chapters.

My JEE Mentor always used to say, to avoid this hosch pcoh (confusion) of what to do : Always plan your day, a day ahead. Means you can plan your tomorrow's schedule, today evening before going to sleep.

In the last answer, I told you to plan what you are going to do in remaining time. Which material you will solve, and you have to that for every chapter. Break down that schedule for each and every day. 

Simply write which three chapters (one of each P,C,M) you are gonna cover tomorrow. What material you will solve, and at what time. 

Make it organised. And put all focus to complete the task of the day. Do it everyday. and you will see the results.

For more personal and interactive session, you can book svayam sessions from our website or you can request Roshni Ma'am through mail for a personalised session. Because it's very difficult to convey each and every thing here.

Nevertheless, always happy to help.

Good luck.