Option for CAS

An employee completed his 24 years of service on 13.03.2023. Can he opt for availing 24 years CAS benefit w.e.f. 01.08.2023. As per ROPA 2019 an employee can opt for CAS either on the date of actual non functional promotion or from the date of next increment. Now, due to introduction of 15 years and 24 years CAS w.e.f. 01.08.2023 an employee who completed 24 years service after 01.08.2023 will be senior than the employee who completed 24 years of service on 13.03.2023, if he can not opt for availing 24 years CAS w,e.f 01.08.2023.