Oslo is 3.5 hours behind Delhi

Best overlap: 12:00 PM to 6:00 PM in Delhi is 8:30 AM to 2:30 PM in Oslo.

For the smoothest call, aim inside 12:00 PM to 6:00 PM in Delhi, i.e. 8:30 AM to 2:30 PM in Oslo. Oslo is 3.5 hours behind Delhi, but you'd hardly notice — 6 hours of shared hours makes this feel like working in neighbouring time zones. Daylight saving complicates things slightly: Oslo observes it, Delhi doesn't, so the difference flexes by an hour part of the year.