We study a on-off feedback method to control the dynamics of a radio physical oscillator having hidden coexisting attractors. The proposed time-varying on-off feedback effectively controls the multi-stability which acts in an on-off manner. We show that for suitable values of feedback strength, feedback active time ratio and time period, the coexisting chaotic and periodic dynamics of the system go to a mono-stable periodic state followed by a stable steady state. This transition from multiple attractors to a single attractor is confirmed by calculating bifurcation diagram, Lyapunov exponent and the basin size as a measure. We also illustrate the generation of chaotic attractor in the system using this scheme.