A win in Turkey would see the Italians, who have a four-point lead in Group B, progress to the next round with a game in hand.
The Nerazzurri end the group at home to CSKA Moscow on December 7.
"We need the three points tomorrow to reach the knock-out stages," Ranocchia told his club's official website www.inter.it.
"It's an important step that we must take.
"To qualify for the next round would allow us to fully focus on the domestic front."
The Nerazzurri are in buoyant mood after a solid display saw them beat Cagliari 2-1 at the weekend to record their third win in Serie A.
Claudio Ranieri's side still has a lot of work to do if it is to compete for the scudetto this season.
They are 16th in Serie A, 11 points behind league leaders Juventus.
"We are slowly getting back on track," Ranocchia said.
"We have improved after the international break and we played good football against Cagliari.
"It was an important result considering that we are still unlucky with injuries."
Inter suffered a setback ahead of their trip to Turkey with Dutch winger Wesley Sneijder ruled out with a thigh strain. Sulley Muntari and Maicon are also unavailable.
However, Ranieri has recovered defenders Lucio and Yuto Nagatomo, who could feature on Tuesday.
Rivals Trabzonspor are confident they can end Inter's three-match winning streak in Europe and surprise the Italians again.
The Turkish outfit beat Inter 1-0 at the San Siro in their group opener and are third, level on five points with CSKA.
Senol Gunes' men are hoping to improve with respect to their goalless home draw against CSKA last time out.
"We were disappointed with that result," Trabzonspor defender Giray Kacar said.
"We missed a chance to go second. Now we must beat Inter and we know we can do it.
"We managed to do so in Milan and there is no reason why we cannot do it again this time in Trabzon."
Trabzonspor go into the encounter on the back of last weekend's 1-1 draw at Mersin that left them second in the Turkish Super Lig, four points behind Fenerbahce.