The Serbia and Montenegro defender is believed to have cost Pompey a club record fee of £1.9million.
"I'm very pleased to get Stefanovic, he's a good player. A left-sided, left-footed centre-half," Redknapp told the Portsmouth News.
"He's a terrific passer of the ball, he passes like a quality midfielder and he's fantastic in the air.
"He's got a great attitude and is a terrific professional. He's captain of Vitesse Arnhem who have been a good club, even if they didn't have such a great season last time around.
"He really wants to win and loves it in England. He's going to spend the rest of his life here and bring up his kids in England.
"Rangers came in strong for him at the end, but he'd already made up his mind that he wanted to come to us."