Dear candidate as per NTA guidelines for 10th class passing certificate -

The candidate should scan his/her Class X Passing Certificate for uploading

Size- 100 KB to 400 KB

Now, consider the case when you upload the xerox. While doing this the original pixels of the image may get blurred and NTA may send you mail regarding this and ask you to upload again.

If you don't get any mail then consider your application to be good. Otherwise you can write an application regarding this and ask your colleges to provide you with the original certificate.

All the best

Hope this helps