Benguluru Nagercoil is running with rake of Sheshadri express operated by SCR. Next time please tag the train name and station to appear in the train forum.
If it's given a separate rakes by SR it xan run from Salem to Benguluru region as intercity express with 3Ac as ACC. Don't think wise to divert via Cuddalore making route long from Salem that too in midnight when people will not take instead prefer bus in evening or morning.