After updating to nougat there is no ringtone in settings of my life vivo v5s

Well there has to be ringtones, plural, however any ones you added yourself may be gone or ones that originally came with the prior version may be gone. Updates can cause both of those things to happen.

Try restarting the phone first, and see if the ringtone you are looking for is then in the list of ringtones again. If it isn't, and it was one you installed, you will have to reinstall it. If it isn't and it is one that came with the phone (prior to the update) then it is probably gone now after the update.