Dr told me have l hip dysplasia. Mri shows asymmetrical hypertrophied muscles on right side -is this to laterally rotate r side to make even with left?

Compensatory changes. More than likely the left hip dysplasia is causing asymmetric gait which is being compensated for by hypertrophy of the right pelvic and leg muscles. Since you do not provide any information about the severity, symptoms or x-ray findings, it would not be appropriate to comment on treatment.
Compensation. The right side is doing more/different work than the left, so the muscles have become larger to handle the extra work.