I applied for RD (submitted at Jan.) but I see posts that the RD results are coming out?
I am likely to be rejected by now?
It is rolling. The first batch came out 12 days ago. There are more to come in upcoming weeks through early April.
Every two weeks?
No. Not on a fixed schedule.
Are only accepted students notified during each wave?
No, but there would be very little rejection in the early rounds.