The study of Inverse Trigonometry typically follows Relations and Functions. So, I would advise you to visit my page Relations and Functions, before proceeding. I am Suman Mathews, mathematics teacher and consultant.
Having taught Math to high school students for close to three decades, I can help you to prepare Inverse Trigonometry just the way you need to learn for your Class 12 exams. Inverse Trigonometry is used extensively in Calculus, so all the more reason for you to learn it well.
To start with, you need to learn the Domain and Range of the six inverse trigonometric functions. In this context, you also need to learn the principal value branch of these six inverse Trigonometric Functions. You'll also learn how to calculate the principal values of inverse trig functions.
The next important point to note is properties of Inverse Trig functions. You'll learn formulas for evaluating negative angles, reciprocal angles and addition and subtraction of certain inverse Trig functions. Keep in mind, that while solving problems using Inverse Trig functions, you need to keep in mind the domain and range.
There are a number of free youtube videos and MCQ Questions and formulas provided in the links below. In case you still need extra help, you can contact me for Online Tutoring. I can help you understand concepts and equip you to solve questions related to the NEP pattern.
You can form groups of 5 to 10 students from your school and learn.
You can contact me on mathews.suman@gmail.com