RAC: Reservation Against Cancellation: You get a seat allotted if you are on RAC and can board the train. When the TTE checks all the seats, if there is vacancy, he is SUPPOSED to allot a berth to you as per your RAC number in that coach.
WL: Waitlisted. Means your ticket is not valid for travel, unless it becomes RAC. Keep checking if you are holding a Waitlisted Ticket. Normally charts are prepared 4 hours before departure of train on the same day, say at around 6.00 p.m. or 4.00 p.m. For the next day's morning trains till 2.00 p.m or so, Charts are prepared the previous day: Say your train is today at 8.00 p.m. Your chart should be prepared...
more... by about 4.00 p.m. SAME DAY. If your ticket is for tomorrow, then chart will be prepared around 6.30 p.m. TODAY ITSELF.
BOTH FOR RAC AND WL TICKETS KEEP CHECKING AT TIME OF CHART PREPARATION: YOU MIGHT GET CONFIRMED TICKET INDICATING COACH AND SEAT NUMBER IF YOU ARE ON RAC. IF YOU ARE ON WL, YOU MIGHT GET ALLOTTED RAC NUMBER AND COACH. MAYBE IF YOUR LUCK IS GOOD, YOU MIGHT EVEN GET A CONFIRMED STATUS INDICATING YOUR COACH AND SEAT !! Good wishes.