By default Joomla doesn't have such a feature. Some time ago I have used alternative registration component for J2.5 which have it - so probably there are also for J3.2 - sorry I didn't check -- but I will...
As you might know you have to use additional component for it - a replacement for Joomla's registration. On JED I have found few (for J2.5 and J3.2) which have "terms and condition" option:
1) ExtendedReg 2) Ultimate User 3) RSMembership! 4) AjaxRegistration Pro