can we travel with 3ac waiting list counter ticket
Yes you can travel only if the ticket is not booked online. You can travel if you have a waitlisted ticket from PRS counter. But you will not get a seat there. However you can ask TTE for available seats as some cancellations take place after chart preparation also.
You are not allowed to board the train if you have an E-Ticket.
We can travel in the preferred class or have to go to sleeper couch.
You may travel in the class which has been booked in the ticket.
No waiting tickets holders are not allowed to travel because all the seats are allocated to confirmed tickets.
What if i have a counter waiting ticket
It has already been mentioned that waiting tickets holders are not allowed in reserved coach.
Then how can we travel in SL coach with waitlisted PRS Ticket
Only confirm tickets holders are allowed in SL or AC coaches, waiting holders can travel in general coach of IInd class only in mean time they can contact to TTE for allocating seat if available in running train.