To check, launch a terminal and execute this command as a user.
$ cat /proc/net/if_inet6
fe80000000000000022401fffed782ea 03 40 20 80 eth2
00000000000000000000000000000001 01 80 10 80 lo
You should see the above output and if you are not , maybe the kernel is not compile with ipv6 module. If so, you can enable it and check if it loaded.
# modprobe ipv6
# lsmod | grep ipv6
ipv6 237436 14
You can run the above commands for all the devices, they are all IPv6 ready.
There are many articles out there to disable IPv6 but with the depletion of IPv4 addresses, I think this practice should not continue but be ready and prepared for it. Of cause unless you got good reason not to use IPv6.