Tickets remain available throughout the year. But for the vacation duration i.e from april last to june first week, getting confirmed ticket in it is bit difficult, specially in 2A. Personally i have suffered this. RSWL 1 didn't even got confirmed even though doing reservations 2 months prior. RLWL, PQWL and RSWL quotas in 2A are very very difficult to confirm.
If in emergency, opt for 3A as it has better chance of getting confirm seats as compared to 2A.