you can neuter your cat a month after all vaccine complete.
if your first vaccine in september, your 2nd vaccine is october. if you neuter the cat on october, this mean you skip 2nd vaccine already. now u need to repeat it again later.
if let say u want to neuter your cat after 2 week of 1st vaccine, you need to make sure your cat can handle this. check with your vet.
normally after a week of vaccine you can't bath them yet (even bath also cannot, now u r going to the stage of surgery). changes in the body system doing its job during that period.
so in this situation, the latest u do neuter is after 2 weeks of the 1st vaccine. now, when u neuter them, for sure they need rest for awhile to make sure the surgery is doing good right and skin complete dry.
can u make it till before October before the 2nd vaccine? remember vaccine won't be given to cat that is not fully healthy. especially for female cat, u need to give them longer rest because they cut their stomach, if u vaccine them too soon after the neuter, they might get in trouble.
normally they do neuter after the age 4 months old..
that is why vaccine start at 2 months old, where - 2 months is the first vaccine, 3 months is the second vaccine, 4 month old when neuter start. so from here you know why vaccine start at 2 months old, and why neuter start at 4 months old = because they refer to the chart, vaccine - vaccine - neuter.
else check with your vet again.
let me know if u don't understand.
Btw, let say i give my cat relax for 2-3 weeks rest after neuter, can i do vaccination and i'm late so i have to do another one?