How to read the chance
Available = 100%A confirmed berth is open right now. Seats sell fast, so book soon. RAC means you can board and share a berth until one frees up.
Waitlist = estimateA rule of thumb, not a measured prediction. It starts from the waitlist number, then adjusts for the class (1A and 2A have few berths, so a WL 3 in 1A is a weaker bet than WL 3 in 3A), the waitlist type (RLWL, PQWL and Tatkal clear less often than GNWL) how close the journey is, and how fast this train's waitlist is moving: how far it has already moved (GNWL 119/WL 60 means 59 waitlisted tickets ahead have been confirmed) and, once AbhiRail has seen the train before, how many places it has cleared per day since. Every night AbhiRail re-checks the trains your family searches; after a few weeks the chance leans on each train's own track record: how often its waitlist cleared that far on past dates.
New trainsTrains launched in the last few weeks, such as the Vande Bharat Sleeper, may not be in the live data yet. They appear with a "New" tag and a link to check seats on IRCTC.