Microquasars exhibit that twin-peak QPOs are shown with their respective frequency correlation ratios. Each solid curve is plotted in terms of their frequency ratios and oscillations radii for a = 0.999, 0.998(dotted), 0.99, 0.98, 0.97, 0.96, 0.95, 0.90, 0.80, 0.75, 0.70, 0.60, 0.50, 0.25, 0.0, −0.50, − 0.75, − 0.999 (from left curve to right). Highest possible resonance oscillation is 2:1 which can occur a ~ 1. Envelop of each curve shows extreme correlation ratio which indicates that even an extreme retrograde black hole can exhibit frequency ratio of 1.35 (dotted horizontal line).