Well normally when you get the reg book for the first time, you have to go to your nearest post office and get it registered within 15 days. Many of us are not aware of this rule.
If it is not done, then you have to visit the ETO office again and they just restamp it after which the post office accepts it for registration and payment of road tax. It does not take much time in getting the reg book/paper restamped from ETO office.
Token tax is not paid at ETO, but at Post office, that is for sure.