Can i use 75mm Mini Fit guttering?

I would like some advice on the following problem that i have-

I have an extension that has a roof 6mts wide by 3.5mts deep.
The existing guttering is the normal size but it prevents me from changing some fence panels. I would like to change the guttering for the mini profile type.
Would this be able to cope with the rainfall from the given size roof?

Thanks.

Why don't you remove the existing gutter, replace the fencing, then put the guttering back up

75mm is really for sheds and the like.