BA 349 then VS 354 at Heathrow
Nice → London → Mumbai
Timetable, London time
21:05BA 349 from Nice at the gate
18:15VS 354 to Mumbai leaves the gate
21 h 10 apart on the timetable, overnight
VS 354 leaves 21 h 10 after BA 349 arrives on the timetable: more than half a day, so not a connection we count.