The 47-year-old has warned his men against complacency and expects a tight match at the Estadio da Luz on Thursday
Fener recorded a 1-0 home win in the first leg but Kocaman believes both teams have an equal chance of making it to the final at the Amsterdam ArenA on May 15.
"Benfica are a more experienced side and have played many European matches. Even with us being 1-0 up in the tie, the chances are equal for both teams," Kocaman, 47, said at a press conference.
"We're facing very strong opponents, we have a one-goal advantage but we're not through yet - we'll only know that after 90 or 120 minutes.
"In the last training session we worked on penalties, but it's more important to be mentally ready to take them.
"We didn't play well in the first game, but we played the way we were able to. Benfica are stronger here and have the home support with them, while we have the result on our side. For me we're even."
Thursday's encounter in Lisbon will kick off at 21:05CET.