Option 1 states that Prof. C.N.R. Rao worked mainly in solid-state and structural chemistry. This statement is correct and aligns with his work and contributions in the field.
Option 2 states that Prof. C.N.R. Rao is the head of the Scientific Advisory Council to the President of India. This statement is incorrect as he has never held this position. Prof. Rao has held several prestigious positions, but this specific role is not one of them.
Option 3 states that Prof. C.N.R. Rao was conferred with China`s top science award for the year 2013 for his contributions in boosting Sino-Indian scientific cooperation. This statement is correct and highlights his recognition and contributions to scientific collaboration between China and India.
Option 4 states that Prof. C.N.R. Rao is a member of the US National Academy of Sciences. This statement is correct. He is an elected foreign associate of the US National Academy of Sciences, which is a significant honor for his scientific achievements.
In conclusion, the incorrect statement about Prof. C.N.R. Rao is option 2 - he is not the head of the Scientific Advisory Council to the President of India.