What is the frequency of overhauling of 33 kV VCB breaker?

Tell us whether the vcb is indoor our outdoor type?

It depends on the breaker type, each manufacturer and style have different specs. You also may fall under other authorities, such as EPRI, that has their own requirement. Knowing more details about your location, facility, and equipment is needed for an accurate answer. But commonly they are overhauled every 10 years (Max), 2000 normal oiperations, or after seeing 2 faults. Which ever comes first.