Raghavan, who earlier served as Deputy High Commissioner in Islamabad 10 years ago, will replace Sharat Sabharwal.
Speculation has been rife over who will attend the swearing-in ceremony of Nawaz Sharif from the Indian side.
India on Friday told Pakistan that it had only resorted to "controlled response" to the "unprovoked" firing by Pakistani army.
200 Indian exhibitors are participating in the three-day India Show organised at the Lahore Expo Centre.
The two discussed matters relating to Mumbai attack and the visit of a judicial commission to India.
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