CA student union

Because a qualified CA is also students once & he is much mature in taking decisions rather than a student.

Yes but the requirements include FCA that is 5 years of practice. He/she was a student and obviously more matured than a student. But i am talking about representation here and not decision making. Decisions are best taken in consultation i.e. ICAI board. Once qualified, interest of students takes a back seat and interest of practice would be in forefront. There is a reason DUSU president is a student, lawyers are represented by a lawyer and so on.