I took an iq test, i was 20 years old.i took the iq test at a mental hospital. i had a iq of 77. what does this mean?

Validity: A simple traditional IQ test would be insufficient to truly gauge your intellectual capacity. On a Wechsler-Bellevue scale your number would be below average, but not knowing the hospital scale, or accuracy of the test, cannot assume any significance. You could have your records reviewed by a psychologist or psychiatrist for a much better assessment.