Employee can only be excluded if he had not been member of PF any point of time before, even if receives the salary more than 15,000/- but he had been member o fPF earlier then he can not b excluded.
Once member of PF is always member unless and untill his PF account is closed. Employee can not withdraw his PF if he is in employment. unemployment is the only criteria where PF can be withdrawn and account gets closed.
You will get a bit detailed information.