How to increase AMD A6-6310 integrated vram

Solution
Yes but more vram doesn't mean more performance if it doesn't get used in the first place. You can always take a look at usage with gpuz for vram and task manager for ram. If you have extra, then you know it's not the issue.
Apus don't have vram on the chip. It has 0 vram and uses ram as vram like pretty much all igpus. There's no point in setting the value manually, it uses what it needs. It's too weak to even use all of its available shared vram. Any performance issues is simply because it's weak and there is nothing you can do about it.