You had paid Reservation charges upto Tpty and from Gudur to Tpty your ticket will be blank paper Ticket. You can board any Sf or exp train to Travel upto Tpty. After boarding first inform to Tte and if any vacant berths available then he will allot to you and your Family. If Train does't have vacant berths, then also you can board and eligible for Travel.
As per my Persobal experience you will get berths from Gudur, but plz choose only Tpty Trains and not passing Tpty Trains.