My family, including children, are traveling to Toronto and have a layover at Istanbul Ataturk Airport for 18 hours. We want to go out to the city and be back to the airport to catch the Air Canada flight to Toronto. We are Indians and carry Canadian PR Cards.
Being from India, you need a visa to enter Turkey. Having an additional visa or residence permit from an OECD country like e.g. Canada, you are entitled as an Indian citizen to apply for a single entry eVisa valid for up to 30 days if you fulfill a few additional requirements: https://www.evisa.gov.tr/
The visa fee is 43 US$ per person.