I had done test for rubella igG and igM both and test results show 0.13 OD ratio for igG and 0.25 OD ratio for igM. What does this mean?

Interpreting titers. Ask your lab about the interpretation of these ratios. The results are generally reported in titers that are either positive or negative. Positive results mean you either have measles, IgM or had then in the past IgG. If they are both negative you require a measles immunization. Ask your lab for their interpretation.