SG 621 then AI 3317 at Mumbai
Udaipur → Mumbai → Patna
Timetable, Mumbai time
20:45SG 621 from Udaipur at the gate
17:00AI 3317 to Patna leaves the gate
20 h 15 apart on the timetable, overnight
AI 3317 leaves 20 h 15 after SG 621 arrives on the timetable: more than half a day, so not a connection we count.