Hello Aspirant

You can't mix-up the best marks of both marksheet, you have to show any one of them.

I'll suggest you to show the marksheet in which overall you have best marks.

You can upload that via filling up forms for govt services also you can upload it on DiGiLocker platform provided by our government.

Also if you are already working and want to update your marksheet than you can mail your organization for that.

Hope this information would be helpful for you.

All the best