SG 621 then 6E 5105 at Mumbai
Udaipur → Mumbai → Chennai
Timetable, Mumbai time
20:45SG 621 from Udaipur at the gate
18:256E 5105 to Chennai leaves the gate
21 h 40 apart on the timetable, overnight
6E 5105 leaves 21 h 40 after SG 621 arrives on the timetable: more than half a day, so not a connection we count.