Hello,

Yes you have to upload it as you are already graduated and completed all  your semesters. For graduates, it is compulsory to upload all the documents. If you don't have originals then you can download from the official page where your results are declared and upload it for registration.

If you don't give all the documents then it may lead to rejection of your application form as you are a graduate. So just follow the instructions and complete the registration smoothly.You can visit the official webpage of gate for more details.

Hope it Helps!