Are you planning on working and pursuing a license in Canada?  If so, your existing degree may be acceptable under the CACB. 

If you don't qualify for reciprocity under CACB, you will need to complete an accredited M.Arch degree in order to start accumulating experience hours (IDP) before writing your exams (ExACs) and becoming a licensed architect in Canada.  Experience hours prior to graduation do not count towards your IDP.

Returning to my question above, if you plan on working in Canada, an arch technology college diploma will definitively help you since it will focus on local building codes, construction methods, etc.  Same with a construction management diploma, although that last one is typically more for project management than building construction / detailing. But please note that these are not accredited, or equivalent, to a M.Arch and will not allow you to start the IDP process.

With that said, you don't need any of these to find a job here, but you will be significantly handicapped since you are unfamiliar (to put it nicely) with the Canadian process and local construction practices. If, on the other hand, you just want a degree(s) to boost your apparent value or social status back in India, then take every course you can and thank you for your international tuition monies.

An interior decorating course has zero value.

Given so many changes in Building codes across the country, green building standards, passive house, detailing etc. some improvement in your technical background would be a wise addition to your skill set.