i applied my visa for may intake 2018 but my visa got late and

[gurpreetgill56895423]

i applied my visa for may intake 2018 but my visa got late and classes were started of may intake when i got my visa and the deadline for defer request has also passed in university which i applied they are not giving me offer letter so now i have my visa can i take offer letter of other college and go to canada or i have to take the same offer letter which i applied in my visa file please help