Had spinal tap. O bands were found in CSF and not blood sample. IgG Index, CSF was 1.20. Does this tell how many bands? Says MS or another disease?

Get diagnosed. The spinal fluid may well be consistent with an immune mediated disorder, but MS is a clinical diagnosis based on history, exam, and MRI patterns. Your neurologist should readily be able to sort out these findings. And no, you do not list the number of oligoclonal bands.
Spinal fluid. Oligoclonal bands in CSF when not in serum suggests immunoglobulins are produced in CNS. It is normal to subtract bands in serum from bands in CSF when investigating CNS diseases, and O bands are an important indicator in the diagnosis of MS. Approximately 79%-90% of patients with MS have permanent O bands. A high IgG index also suggest antibodies in CSF which may be due to MS.