If you are an Indian passport holder, voluntarily acquiring citizenship of another country, results in automatic loss of your citizenship as per The Indian Citizenship Act, 1955. However, you are still required to surrender your passport at a nearest Indian Mission.
India may give you a grace period of 3 months to use your Indian passport from the date of acquiring a new nationality. However, it is recommended you surrender your passport as soon as possible and use your Canadian passport for travel because you WILL need your Canadian passport to enter Canada. You may need to apply for a visa to enter the Union of India on your Canadian passport. So, plan ahead
Citizenship certificate in most cases takes upto two weeks to arrive. Maybe if you get an in person oath, you can get the certificate the same day.
You can get a passport in 48 hours(after receiving citizenship certificate) with proof of travel, if you apply in person at Passport Canada and not by mail to Service Canada.