I spoke and sent an email to Air India customer services. They are saying that I have to re=checkin at DEL, strangely the AI-Bot on the website says my baggage will be sent to the final destination. Very conflicting statements by various people, dont know whom to believe. But the non worrying part is that I have 4h45m transit at DEL, so even if there is any delays with fog or a/c rotations in the morning, I think I should be fine.