senal said:
i am from sri lanka i have both canadian and america visa after 6 months stay in canada should i go back to my home country and how long should i stay there if i want to come back or i could stay in america but how long should i stay before returning to canada
Depends where in America, if you only visit the USA the VISA doesn't restart, so you have to wait the full 6 months to wear out untl you can apply for a new entry. If you are in other parts of America (Caribbean, Mexico, Argentina, etc.) then you can come back anytime.
Remember that the main concern of the officer in the POE is that you are visiting, not living, that means you should be spending more time OUTSIDE Canada than inside. So expect to be asked questions of the purpose of your visit as well as to show documents to support those claims.