yes u can get tkt surely and since rac 3,4,5 good chances of conformation
process:
1) write a letter to station master for issueing of duplicate tkt and go to his office.
2)take a valid id proof xerox of pax who is going to board that train
3)...
more... then same normal procedure go to prs counter and submit the letter& xerox and ask for duplicate , imp thing u need to pay 50% amount extra of total cost.