My hba1c is 27mmol/mol , what is this converted to a blood glucose reading like on my meter in mmol eg 5.0 etc?

Since the HbA1c is: An average, you can't convert it to what your blood sugar reading are. Alternating high and low blood sugars will average out to the same number as consistently normal blood sugars.

Normal: A hba1c of 27 mmol/mol corresponds to 4.6% in the us. This is a normal level, and means that your average blood sugars are normal (4-5.6 mmol/l before meals). You cannot use hba1c to try to make a diagnosis of hypoglycemia or low sugars.