can i update my iphone 3gs 4.1 to ios 5 - 6

i want to know can my iphone 3gs 4.1 update to ios 5 or 6. because i tried updating from itunes ios 6 and when it successfully installed, it ask me to activate my iphone so i follow the instuctions but failed to activate, i tried more than 10 times. then i went to a handphone shop then i ask him why can't i activate my iphone and he said iphone 3gs does not support ios 6 he say it must be on a 4.0 or 4.1 cannot be more than that. but i saw an iphone 3gs ios 5.1.1 online.

so i'm confused the handphone shop guy says (iphone 3gs does not support ios 6 must be on a 4.0 or 4.1 cannot be more than that) but i saw an iphone 3gs ios 5.1.1 online! 😕

So can i or can i not update to ios 5 or 6