Train 16525 / 16526 must be diverted via Salem - Erode - Karur - Dindigul - Madurai - Virudhunagar - Kovilpatti - Tirunelveli - Nagercoil to reach / depart from Kanniyakumari because there is not enough trains for Salem, Erode and Karur passengers to reach the South TN. Do not talk about 16609 / 16610 and 17235 / 17236.