I had a Bone Density test. The result was : R-6.59 L-6.20 Lumbar 9.82 What does this mean?

Numbers look wrong. Central DXAs measure bone density at the lumbar spine and left and right total hips/femoral necks. Results are presented as actual BMC (bone mineral content (ie, 0.887, 0.7436, etc) and as a T-score (standard deviations above/below ur bone density is from woman's peak bone mass). T-scores are usually presented as a + or - number: >-1.0 normal, -1.0 to -2.4 osteopenia, .
T-score. For postmenopausal females T score less than -2.5 signifies osteoporosis. I'm assuming that R and L in your question is referring to right and left femoral necks. Good health.