Step-by-Step Deduction

To determine which vehicle C travels in, we can use the process of elimination based on the given clues.

1. Clue (ii) tells us about the Swift: "B, a male engineer, travels with only G, a teacher, in a Swift."
   This means the Swift is full with only two passengers, B and G. Therefore, C cannot be in the Swift.
2. Clues (vi) and (i) tell us about the Creta: "The pair of sisters A and F travel in the same vehicle," and clue (v) places them in the Creta. Clue (i) explicitly states, "C ... does not travel with the pair of sisters A and F."
   Since A and F are in the Creta, C cannot be in the Creta.
3. Conclusion by Elimination: There are only three vehicles: Swift, Creta, and Nexon. Since C is not in the Swift and not in the Creta, she must be in the only remaining vehicle.

Final Answer

C travels in the Nexon.