I am from India and am an Indian citizen. This month I am planning to go to Canada (I have a Canadian visa). On the way I want to visit South Korea for 7 days. My friend told me if I have a Canadian Visa in my passport a Korean visa is not needed, I can get a transit visa in Korea airport, is it true? What Documents would I need for the transit visa? If I need a visitor visa I must apply in India.
If you are transiting South Korea on your way to Europe, USA, Canada, Australia, or New Zealand, then you can spend up to 30 days “in transit” without requiring a South Korean visa. This applies to Indian citizens.
As you are planning to go for 7 days, as long as your plane ticket to Canada is booked before you go to Korea (which you said it is), and you have a Canadian visa in your passport (which you said you do) you will be able to spend the 30 days in transit. They will stamp your passport with the visa when you enter the country.
Official source: https://www.vfsglobal.com/korea/india/transit-visa.html
Source from a blogger who has done this before: https://bkpk.me/south-korea-visa-for-indians/