What I mean is that if you have an engineering degree then you would be able to apply only for the general cluster which will include PAS, PSP, FSP etc. But you won't be eligible to get selected for IRS as you do not have a finance degree, even if you clear the exam and get merit position in the range of IRS, you still won't get an allocation. On the other hand, someone with an accounting degree will be able to apply for both General and Accounts cluster and he can be allocated according to his/her merit.