If you are a healthy adult , 90/60 is considered to be normal.
The first digit is called systolic and the second is called diastolic blood pressure.So your systolic blood pressure is 90 and your diastolic blood pressure is 60 mmHg.
In adults a diastolic pressuire<85 mmHg and systolic pressure<130 mmHg indicates normal blood pressure.
These levels for blood pressure are arbitrary levels which have been stablished to define persons who have an increased risk of developing a morbid cardiovascular event and/or will benefit from medical therapy. For example patients with a diastolic pressure>90 mmHg have a significant reduction in morbidity and mortality rate
if they receive adequate therapy. They , then , are patients who have hypertension
and who should be considered for treatment.
It also depends on sex, age, race, and concomitant diaeases. For example for diabetic patients the blood pressure should be less than 130/85 mmHg . In the first year of life the acceptable levels are 90-100/60-67 mmHg and in the late teens 100-120/65-75 are considered normal.