Dear @KumaraRaja.Eedara,
A similar question was discussed in the following forum topic: Azimuth Angle of the Blade. Basically, in AeroDyn v15, the local blade azimuth angle is defined based on how the rotor disk-averaged relative velocity projects onto the disk (based on the skew angle between the rotor axis and inflow) rather than some rigid-body rotation of the rotor. If you want the later, I would use the Azimuth output from ElastoDyn instead.
Best regards,