Oslo is 3.5 hours behind Chennai
Best overlap: 12:00 PM to 6:00 PM in Chennai is 8:30 AM to 2:30 PM in Oslo.
Keep meetings inside 12:00 PM to 6:00 PM in Chennai — that maps to 8:30 AM to 2:30 PM in Oslo. Oslo is 3.5 hours behind Chennai, but the generous 6-hour window means both teams can meet well within their normal day. Remember that Oslo shifts for daylight saving and Chennai doesn't, so recalculate the overlap after each clock change.