at present i don't have central EWS so now i can submit the form of CUET PG by giving the State EWS.as i will get my Central EWS certificate after few month due to some documentation problem.so i can subbmit the Central EWS during addmition.what should i do will my form reject by giving State Ews

No. You should not fill Central EWS using a State EWS certificate.

For CUET PG , only Central EWS is valid. State EWS is not accepted .
Your form will not be rejected now, but during counselling or admission , if you fail to show a Central EWS certificate , your EWS claim will be cancelled and admission may be affected.

Best option:
Fill the CUET PG form as General category .
Apply under EWS only after you receive the Central EWS certificate .