Yes it seems that both Karachi kings and Quetta Gladiators will finish fifth and sixth position and therefore they will be eliminated from this tournament.
Check their performances and both of them have won a total of 3 matches of the 14 (8+6) matches they played. Karachi kings have played 8 matches and won only 2 of them. Similarly, Quetta Gladiators have played 6 matches and won only 1.
Do not think that now the remaining matches will be of no use as the top 4 teams would qualify. No, the position of the teams does matter as the team that finishes with 1st or 2nd position will get a double chance in the playoffs while the team ending up 3rd and 4th with play a knockout game.