@restroyerz
As @EA_Mai pointed out, all you would need to do is provide proof of ownership (physical retail copy, for instance) and contact a Game Advisor.
I am currently moving and I found a bunch of my old game CDs, and I wanted to convert them all to digital copies (as the physical discs will degrade over time, or can scratch, get ruined, etc.) The Sims 2 "Special DVD Edition" was one of the games I found. I didn't even bother coming to Answers HQ, but figured I'd fill out the ticket and take a picture of my Sims 2 CD case fanned-open to show the cover and the gamekey in the same shot. Several minutes later, I had the Sims 2 Ultimate Collection in my Origin Library! I was happy and surprised -- as I know the game is old, and I never knew about the FREE GIVEAWAY for it in 2014. So, I left really positive feedback for the EA Game Advisor because I appreciated it.
If you just want to purchase the Sims 2, check online for someone selling the physical copy (as I'm unsure if there are any other digital distributors allowed to sell it.) If you manage to find a CD for sale, buy it, and then follow the outlined steps if you want to see if they will add it to your Origin Library.
Good Luck!
-skullified