Hello Aspirant,

Unfortunately, now you cannot upload certificate on the place of your declaration of category certificate because you can upload it only once. There is nothing to be panic about it because if you will be alloted a seat through JOSAA counselling then you have to show your caste certificate which should be issued after 01-04-2020 in the online verification of documents through alloted Institute. Note that with that declaration you will be considered as OBC candidate until and unless seat is alloted to you and as the seat is alloted you have to submit the original certificate for your category.

For more details about JEE-Advance Application refer to the link given below :-

https://engineering.careers360.com/articles/jee-advanced-application-form

I hope this information helps you.

Good Luck!!