Hey Naaz,
Firstly, u can get married anywhere where you want as long as Canada recognizes that country marriage certificate.....so can marry in India, Uk, Jamaica, Mexico, Canada or the US etc depending on if both of you can get a visa to the place.
Secondly, there's nothing as applying outside the Uk or appplyin inside India...base on what you've said, you can only do an outland application since both of you are not staying in Canada.
Plz I will advice you to go the CIC website and do a thorough reading on how to fill the forms and where to sent it to.
http://www.cic.gc.ca/english/information/applications/guides/5289ETOC.aspThird, if he had stayed for over a year or had a year on his visa when he was admitted into the Uk, then U can request that your application be process forwarded to the CIC Uk office after the first approval stage, or the file will be forwarded to CIC india. however, it take about 8-12 months for the file to be complete in Uk and7-12 for India.
I hope this help.