Hi aspirant

If you are taking admission even if you have backlog in any paper then you will have to upload a copy of any marksheet of the final year issued from the institution.It should not be internet downloaded.

And if you wish you can appear in GATE next year as well .there is no such problem to which you should worry.Its ok if there is back.You will not face any problem neither this year nor after that.

Visit the link for reference:https://engineering.careers360.com/articles/gate-eligibility-criteria

There are much more things in the post which might be helpful to you.

Hope this was helpful.