Hello Aspirant,

EWS certificate is applicable only for those general catefory candidates ie., candidates who are not covered under any reservations (such as OBC, SC, ST and except PH and Ex-servicemen criteria) and belong to economically backward sections.
And there is only one EWS certificate which you can get from your state authority. In India there is no such distinction such as state and central EWS certificates. So the EWS certificate you have got from your state's concerned authority (eg. Tahsildar office),  is valid all over India. The validity of EWS is one year.

All the best