Mr. Pawan gave the perfect reply!!
Do ask TTE b4 boarding train!!
I dunno ur travel day bt LTT-RNC Exp do hav berth available (nt everytime although)..as few times hav traveled like: GR till JBP & RNC Exp till ALD (smetimes SL n smetimes 3A get AVL...nt bth same time although)!!