There is no specific advantage of a Cambridge A level student in NEET. Rather I would say they have a disadvantage. IGSCE allows use if calculators in subjects like physics, maths, chemistry. This habit is a bad one because one shall not be provided with such in entrances like NEET. The level of accuracy and speed is an important factor in entrances, and clinging to habits like automatic uses may harm this very talent.

Moreover, I would say CBSE has an edg over it becaus most of questions in Biology come directly from NCERT textbooks. Even portions of chemistry like inorganic are copy and pasted. Hence, if you would ask me I would say to go for CBSE keeping in mind trances.