how could i backup contacts of iphone 6 plus

I have my iphone 6 plus and operating in Canada with Fido - now I am visiting India for few months and would like to use a new sim in this phone after unlocking it by FIDO but fido told me that upon unlocking and with new Sim you woulkd loose all contacts and photos - thats why I would like to back up my contacts and photos before unloclking it and before using new sim.