Dear Unnat,

Do not study NCERT first. IT has some concepts define with so much brevity that you'll find it hard to understand them. Rather I suggest you should study a help book first, clear your concepts use videos if you find it necessary and then when you are comfortable with the concept open NCERT.

Moreover, never leave NCERT even if you have studied the topic from some other book. NCERTs are one of the best textbooks available and you should go through them if you are preparing for a competitive exam.

Thank You.