I have got my visa, Can i withdraw my application cuz circumstances are forcing me to withdraw application. Then can i apply for new study permit and new loa.
Will i get visa second time, or will i face any difficulty?
Bruh. Why are you starting 4 threads asking the same?
You can't withdraw your application once it is approved. You should contact ircc to see if they can cancel your study permit or you shouldn't start your studies which will result in college notifying ircc and then they will cancel your study permit.
Since you want to re-apply after changing the dli you have two options. One is to go to Canada 3 weeks prior the current start date and requesting your dli to change the dli. Second one is about notifying ircc to cancel the study permit, wait for a decision and apply for a new study permit.