Can someone please advise what are the next steps after we take the oath ceremony.
I'm a permanent resident (Indian citizen) , do I have to apply for Canadian citizenship certificate separately or do I get it during the Oath ceremony, the same day?
You get your certificate at the oath ceremony. You use that certificate to apply for a Canadian passport. Note that you usually need to wait a day or two after the oath ceremony to apply for a passport. This is because the system needs to be updated with your new status as a Canadian citizen.
One extra step for you (as an Indian citizen) is to apply for OCI status.
Do I surrender Indian citizenship first, apply for OCI and then apply for Canadian passport or first apply for Canadian passport and then surrender Indian citizenship