Do you think Sasuke realized...

[Neji Hyūga2]

Honestly I don't think Sasuke realized it until then possibly. I'm sure he didn't really go back and started thinking about those old times randomly.
After that explanation he probably guessed that Gaara was one of those Jin's and didn't give it a second thought.

 

[lndra]

Didn't Sasuke say something interesting when Gaara turned into Shukkaku? Or was it when he saw Naruto transform Gamabunta into the Kyuubi?

Amma go say no (probably), because I doubt the Bijuu is something you can learn in a textbook. They even kept the 9 tails a secret from the Jinchuriki.

 

[HENI]

yea he realized

 

[Solo]

Sasuke probably didn't make the connection until the saw the Tailed Beast during the war. Only Tailed Beast he knew was the Nine-Tails from Konoha history. For all he know, that could have been a summoning.

Plus, the fact he asked about the Kyuubi(Naruto) means he didn't know any other Tailed Beast/Jins at the time.

It's more than possible.

He never put together (on screen) that Tobi's attack was the driving force behind the Uchiha being massacred.

Uchiha would have been killed regardless Nine-Tails attack. Tobi's attack was the justification for it. Tobi also told Sasuke he never release the Nine-Tails on the village.

 

[WalksInShadows]

i believe that last page pretty much summed it up that he didn't.

 

[shelke]

Sasuke didn't know what a Bijuu was. He probably thought it was some strange, separate entity within Gaara. He had no idea what Kurama was either. It makes sense, as he was just a genin. Him being privy to the information wouldn't seem right.

Your question is a bit confusing. Are you asking that he realized back then that he was a Bijuu, or after this dialogue from Obito? For the former, I believe the above information would suffice. For the latter, I think it is obvious that he could have realized it. He was asked to procure one after all.