AI 2975 then SG 9553 at Mumbai
New Delhi → Mumbai → Gorakhpur
Timetable, Mumbai time
08:55AI 2975 from New Delhi at the gate
21:25SG 9553 to Gorakhpur leaves the gate
12 h 30 apart on the timetable
SG 9553 leaves 12 h 30 after AI 2975 arrives on the timetable: more than half a day, so not a connection we count.