so the rule applies as per the below ,when you apply you have to be residing in Canada and residing in Canada means not physically present by actually residing .this clears the first part of my question .For clarity on the issue please refer guide imm5772 which states as under:
Who is eligible:
You live in Canada.
(This is of course in addition to several other conditions)
Who is not eligible:
you won’t live in Canada when you apply to sponsor your parents and grandparents and/or when your parents and grandparents become permanent residents
Your primary residential address must be in Canada when you submit your application and until we make a decision on your application.
Hope this will answer your query.
There is no requirement that you (the sponsor) or your co-signer (if applicable) have been a permanent resident, Canadian citizen or Status Indian for the 3 years immediately preceding your application to sponsor in order to be eligible to sponsor your parents and grandparents; however, you must be a Canadian citizen, permanent resident or Status Indian living in Canada when you submit the application.