No, based on the information available on the Guru Gobind Singh Indraprastha University (IPU) website, you cannot upload a declaration form in lieu of the EWS certificate at the time of registration for IPU counselling.

The official brochure for IPU counselling typically outlines the documents required during registration and verification. These documents usually include the EWS certificate itself, not a declaration form in its place. During IPU counselling, there's a verification process for candidates claiming reservation benefits under categories like EWS. This process likely involves verifying the original EWS certificate issued by a competent authority.

https://media.careers360.com/articles/ggsipu-cet-bjmc-counselling

I hope it helps!