Which plan is called a rolling plan?

Rolling Plan was the sixth five year plan introduced by the Janata Government for the time period 1978-83, after removing the fifth five year plan in 1977-78.You can read about the National Institution for Transforming India (NITI Aayog) – A Brief Overview in the given link.

Further readings:

1. Planning Commission
2. NITI Aayog “Strategy for New India @75