Retrospective inclusion of one reserved category to another reserved category.

Can any state government ammend the GR of giving reservation retrospectively for including the candidates of another reserved category whose reservation has been cancelled by supreme court in an ongoing recruitment process??. This reserved category was firstly in open catagory then the supreme court cancelled their reservation. Second reserved category is EWS catagory in which open poor candidate having EWS certificate are allowed to take benifit. At the time of starting of recruitment process, the reservation was alive and EWS reservation was also allowed.but later when supreme court cancelled this reservation and hence govt give those candidates a chance to change the catagory of reservation in a reserved category i.e. EWS catagory in the recruitment process started 2 years before.i.e. retrospectively. So can any state government through a GR ammend the law through which the candidates of one reserved category whose reservation is cancelled are transferred to another reserved category retrospectively in an ongoing recruitment process?