Can I download GTA V on my PS3?

On the off chance that you have just been ripped off buying a disk which requires you to download the game from PSN (thus making the disk totally useless) it's quite possible your sister would need to activate your PS3 against her Playstation Network Profile. The steps, found here, are:

1. On the XMB, go to PlayStation Network icon > Sign In PSN icon to sign in to your Sony Entertainment Network account.

2. Highlight Account Management icon and press the X button.

3. Highlight System Activation icon and press the X button.

4. Highlight [PS3 System] and press the X button.

5. Select either "Game" or "Video" for the type of content you wish to download onto your PS3 system.

6. Select "Activate" if you want to activate your system or "Deactivate" to deactivate your system.

7. You will receive a confirmation message indicating the process was complete.

Of course, whether your sister does or not is another matter as there is a limit to how many systems she can have activated.

As of November 18, 2011, number of systems for activation is:

• For Game Content - Two (2) PS3 and/or PSP systems

• For Video Content - Any Seven Devices (7) - PS3, PS Vita, PSP, PlayStation TV, Xperia phones, Sony Tablet and Media Go

If you exceed this amount, you will need to deactivate a system before the new one can be used to download content. You must also have the system with you in order to activate or deactivate it.

However, as you said in the original version to your question:

I bought her the disk

you should be able to borrow it from her and play it just fine on your own PS3, unlike Digital Downloads — which require activation to run — a disk does not and can be run on as many systems as you want. This is why you can pick up second hand games from the bargain bin/pre-owned shelf.

Of course, if you can't borrow the disk from her then you're out of luck. Owning a physical copy of the game does not give you access to download it from PSN and vice versa.

No. When you purchased the game you bought a license for one user, your sister. You cannot download it based off of owning the disk only.

You could borrow the disk and play it just fine, but in order to install and play it from your HDD you would need to purchase a new license from PSN.